"You're wrong, you know? I don't want to destroy the world, on the contrary; I like flowers, and trees, insects and animals. The only thing I hate, is all human beings."
Shinobu Sensui (仙水忍, Sensui Shinobu) also known as the Black Angel, was the main antagonist of the Chapter Black Saga, as well as a former Spirit Detective in his youth, having been recruited by Koenma for his prodigious talents and his unequaled sense of right and wrong. He is also one of the archenemies of Yusuke Urameshi (alongside Suzaku, and Younger Toguro ).
Sensui was a tall, broad shouldered, long-limbed man with tan skin, an ovoid jewel in the middle of his forehead and a rather long neck. He normally kept his hair slicked back, with a bang arching slightly over his forehead. He wore a casual long-sleeved gray shirt, dark gray jeans with a matching black belt on his waist and a matching shoes making his outfit into a shades of gray. Though the unusual length of his limbs gave the illusion of a slender build, on one occasion after he lost his shirt it was seen that his torso was quite muscular. This occasion also revealed that his torso, shoulders and arms were all covered with a great deal of heavy scarring, which Sensui inflicted upon himself as part of his combat training. His Kazuya personality also has the ability to morph his right hand and part of his forearm into a gun barrel.
In his Defense Form while utilizing his Sacred Energy, his long sleeve gray shirt is covered in a yellow spirit armor with light yellow sleeves to cover his arms, a yellow loincloth which is connected to his gray shirt adorned with a white belt and a matching sash which is hanging loose in each sides on his belt, light yellow pants with light cyan kneepads on his knees and his black shoes from his casual outfit. He wears a yellow steel pointy hat which it was connected to his yellow armor.
In his Offense Form after switching his Defense Form, he wears a light blue armor with several spike designs at the back, underneath his armor is a black long sleeve v-neck catsuit with white kneepads on both of his knees, a matching ankle length boots in triangular design and white spiked gloves.
In his younger years, he had an unstyled haircut and wore clothes similar to his current attire but in a shades of blue as his long sleeved shirt is indigo and his jeans are medium blue while retaining his black shoes from his current attire. In a flashback dating back to his times as a student, he was seen wearing a gakuran, a Western-style school uniform.
The original Shinobu personality, before his madness took hold, held extreme black and white views on the nature of the world. As such, he was as virtuous as humanly possible to those whom he considered righteous, but was utterly ruthless with regard to all those who he believed to be evil. This perspective enabled him to kill demons for years, often quite brutally, without feeling even the slightest hint of regret or remorse. However, his views of the world began to change somewhat after meeting the demon Itsuki, who was accepted by Shinobu as his partner despite being a demon. According to preceding Spirit Detective Kuroko Sanada, Sensui was said to have had an air of someone with many thoughts on their mind; always thinking in order to keep himself sane and afloat.
His views on the natures of humans and demons were turned disastrously upside down after witnessing a horrifying ritualistic celebration known as "The Feast of Human Vices", at which humans were sadistically torturing demons to death for their own pleasure. Seeing that humans were capable of evils at least as great as those of the demons, Sensui's mind snapped. Unable to cope not only with the contradiction to his black and white views of the world, but the fact that he had unwittingly slaughtered many demons who may not have deserved it, Sensui went on a murderous rampage and butchered virtually all of the attendees. The rampage, combined with Sensui's guilt and his inability to adapt his thought processes to reality, caused him to develop dissociative identity disorder, creating the first of his additional personalities, the sadistic murderer Kazuya, to take responsibility for all the killing he had done.
Upon his reemergence from the recesses of his psyche during his first fight with Yusuke, the original Shinobu personality retained the polite demeanor of his youth, but was openly and obviously deranged, laughing madly when he activated his Sacred Energy for the first time. He also appeared to have little issue both hurting and killing at least humans without any mental shielding from his additional personalities, as he not only killed Yusuke but rather sadistically broke his arm while making a pun about it. However in the anime, he was visibly disturbed by having to kill numerous encroaching demons while in Demon World, and he had a curious sense of honor which shone through when he allowed Kuwabara, Kurama and Hiei to attempt to avenge Yusuke's death. He was also extraordinarily intelligent, and was able to successfully manipulate, predict, and outmaneuver all of Spirit World's greatest assets and planners to succeed in not only opening a tunnel to demon world, but destroying the Kekkai Barrier.
Possibly due to creating six other personalities to specialize in certain tasks, Shinobu has been known to be more complete than the other six personalities as it was stated his anger, calmness and the other polarizing aspects of his personality come together. It is implied this "completeness" is required to master Seikoki as Shinobu stated he is the only one to be able to use Seikoki.
As Sensui fomented his plan to wipe out humanity, he developed six other personalities to both carry out and take responsibility for all the immoral actions he would need to perform. As he developed more and more of these personalities, his original self rarely ever surfaced at all. For instance, Sensui's second confrontation with Yusuke was the first time the original Shinobu personality had expressed itself in many months prior. Four of these six are nameless (in the official story), and three of these four have tasks for which they were created. These three personalities were never named in the manga or anime, but were described by the author in a later interview.
The personalities are:
- Minoru, is the orator and suave manipulator, and is in control for most of the Chapter Black saga. He was created to persuade the six other psychics to join his cause. He is described by Itsuki as a prideful man who talks too much. Of the known personalities, he is the second spiritually strongest after Shinobu. He shares his name with Minoru Kamiya, Sensui's comrade in the Chapter Black saga. His color in Shinobu's mind is light green (talking with his other personalities for the last time) or purple (when Itsuki talks about the other personalities, the one looking the calmest is purple which fits right with his trademark purple energy aura and attacks). Minoru seems to echo Shinobu's sentiments, showing passionate kindness to animals, as proved when he allows a butterfly to rest on his finger before he started his fight with Yusuke in earnest.
- Kazuya is a violent foul-mouthed personality, formed in the wake of the breakdown Shinobu suffered upon crashing the Feast of Human Vices all those years ago. His emergence causes the formation of a gun barrel over his whole right hand, but he is not the strongest of the seven personalities. He was the killing specialist of the known personalities, deriving sadistic pleasure from incapacitating his victims, and was known to kill puppies and small children for his amusement. He says that he was created to do the dirty work; all the stuff that Shinobu and the others couldn't tolerate, much less do. As such, he is the physical manifestation of Shinobu's hatred towards humanity. He shares his name with Kazuya Hatanaka, the second husband of Shiori Minamino (Kurama's human mother). He seems to possess great physical strength, but apart from a surprise attack with his hidden gun, he was by far the least effective personality in his attempt to fight Yusuke. In Shinobu's mind, he is represented by the color red, likely for the bloodshed he causes. Despite being the killing specialist, Yusuke mentioned that Kazuya was actually too weak to beat him and he stated Minoru would stand a better chance against him than Kazuya would. This implies the only reason Kazuya backed Yusuke into a corner was because he was caught off guard since he was not aware of Sensui's split personalities until Minoru switched to Kazuya and used his hidden gun.
- Naru is a childish and sensitive female figure in charge of Sensui's non-violent emotions, oftentimes emerging late at night to cry over the implications of the plan. She appears to emerge only in front of Itsuki and, according to him, composes the most beautiful poetry he's ever heard. This personality is the one that he loves, second only to Shinobu, and he goes so far as to imply that the two of them are in love. Like Sensui, she cares about the Human Realm, but understands humans must die for their sins. Her color in Shinobu's mind is green. This personality is not named in the English dub.
- George is a master of all types of weapons that Sensui may need, and he may have Kazuya's gun(though Itsuki states that only Kazuya can form the gun). It is implied through the anime that George is also foul mouthed like Kazuya, but leans to be more cynical then deranged. His color in Shinobu's mind is light blue.
- Makoto takes care of the burdening errands that Sensui would have to deal with: shopping, cooking, cleaning, driving, etc. It is implied through the anime that Makoto is the one with his eyes shut and never speaking both when Itsuki explains Sensui's personalities and in the background with George while he sarcastically remarks about Shinobu's extreme love for the world. His color in Shinobu's mind is orange.
- Hitoshi is the part of Sensui that cares the most about animals and plants. He was the one who likely convinced the five other personalities that the ningenkai's only problem was humans. It is implied that Hitoshi is the one that looks somewhat disgusted during Itsuki's explanation of Sensui's personalities. In Shinobu's mind he is yellow.
Since birth, Sensui was said by Koenma to have been naturally gifted with immense innate spiritual power. As he matured however, these gifts burdened him with their uncontrollable presence, including allowing him to naturally see apparitions and demons, and even attracted demonic entities to try and attack him due to them sensing his immense spiritual power in turn. As such, since a young age, Sensui was born into a life where he would be forced to learn on his own how to defend himself against something others could not grasp nor see, and often have to fight back against demons as a common occurrence. Reaching his teens, this almost prodigious spiritual power, along with his black and white view of the world and desire for justice made him a perfect candidate to become a spirit detective, and he quickly adapted to the job. Throughout his job as Spirit Detective, Sensui wasn't satisfied so Sensui was partnered with Itsuki, much in the same capacity as Botan is to Yusuke; it is revealed that he was once sent to hunt him down, but Itsuki convinced him otherwise and then became his partner. Over time, Itsuki's stories and nature began to convince Sensui that demons were not all as evil as he had once believed, but he largely maintained his views that humans were good and deserved protection while demons, by and large, were evil and deserved to die if caught in the human world. However, this sentiment was turned upside down when he crashed the Feast of Human Vices and witnessed the Black Black Club torturing demons for their own amusement.
Considered one of Spirit Realm's most crucial and critical cases, the mission entailed the gathering of major kingpins and dons of the Human World's underworld black market demon trade, which if successfully brought down, would have potentially stopped this aspect of the criminal underworld's most lucrative and potentially dangerous new trade. But as the mission lead into the Feast of Human Vices, horrified by what he had witnessed, and his mind on the verge of snapping, Sensui flew into a rage and slaughtered everyone there, but flashbacks in the anime hint at Sakyo and several bodyguards leaving before Sensui suffers his psychotic break. His black-and-white perspective of the world, and the true nature of humans, consumed his mind so much that he subconsciously developed dissociative identity disorder in an attempt to protect himself from the truths that his beliefs would not allow him to accept.
Due to the trauma and feeling immense responsibility for the aftermath of the mission, Koenma dismissed Sensui from his duties of Spirit Detective. Still curious as to the spectrum of the worst aspects mankind held, Sensui took the Chapter Black tape from Spirit World's archives and left back to the Human World with the intent of understanding mankind's potential for evil. However, the tape's visceral and extreme real life footage of historic events of the worst of mankind would only create more questions and paradoxes onto the values and broken psyche of his, and in turn would only lead him to despise humanity even greater than the demons he had fought. With Itsuki, and learning that he was diagnosed with a severe form of terminal cancer, the two would then assemble a team of seven psychics that was intended to help bring an end to the human race.
Sensui first appears in the ruins of the Dark Tournament after being drawn by a mysterious energy signal from Elder Toguro, who was then placed in a fishing tank to recover his power while informing the former Spirit Detective of his successor's actions. Knowing that there was now an opposition to his goals, Sensui would begin his opening of a tunnel to Makai to begin the end of humanity by enlisting five psychics to aid him, with Kaname Hagiri being the most loyal of his followers.
After Yusuke's encounter with Murota, he would appear to the new Spirit Detective to introduce himself whilst ordering Sniper to wound the telepathic amateur boxer. He would then send Doctor and Seaman as guinea pigs to test Yusuke's morality and awaken Kuwabara's new power. After Koenma's explanation of his past, Sensui and Hagiri would appear to the protagonists with the implied intention of testing his power against Yusuke, who he manage to dominate with superior fighting style and energy manipulation; although it is truly to draw out Kuwabara so that he could be more easily captured by Gamemaster and Gourmet. Sensui would take a tactical retreat in the car Gamemaster was driving with Kuwabara held captive. Yusuke realizing this, would chase them with a bike, only to be stopped by Sniper; while Sensui and his group would escape to their hideout.
After being saved by Hiei, the group enters the cave to combat in a intellectual and drawn-out battle with Gamemaster, Tsukihito Amanuma; resulting in the unfortunate death of the misguided child. Burning with new hate for Sensui, the group would enter the cavern holding the almost opened tunnel to Demon World to meet with Sensui, Itsuki, Sadao Makihara the Gourmet and a captive Kuwabara. Sensui knowing that his key to his goal was still powerless, he would decide to return him with the condition of the group defeating Gourmet.
After Kurama had easily dealt with "Gourmet" (who turned out to be Elder Toguro, who had long since taken over the witless man's body), Itsuki would separate the group by having his Uraotoko "devour" them and spit out Yusuke, so that he and Sensui could fight without interference. After a long and hard fought bout, Yusuke caught Sensui off-guard and used the opportunity to pummel him.
In the midst of this battle, Sensui does the unexpected by firing a point-range energy blast through Yusuke, and then revealing a even more unexpected surprise, the "Sensui" he was fighting was one of his seven different personalities, being the suave Minoru, who had now been replaced by the psychotic and homicidal Kazuya. After a short dominance of both unpredictable sadism and insanity, Kazuya had defeated Yusuke in a few shots of his blasts, and was about to kill him, when Koenma shows up in an attempt to have his former detective call off his ludicrous ambition or be sealed away forever by his Mafuuken.
With enough time, Yusuke recovers and easily beats Kazuya; forcing the gentle, yet brutally efficient original persona Shinobu to appear. In seconds, Shinobu manages to break Yusuke's arm, stomp on him several times, dodge his punches and shake his hand before he could even react, it became even worse when Shinobu revealed his true power: Sacred Energy, a force that was so powerful that the cavern began to crumble around them. After a short fight, Sensui had become immune to Yusuke's attacks and even negated the Mafukan afterwards, when Koenma used it as a last resort. However, Yusuke refused to give up.
Koenma tries to dissuade Yusuke from fighting Sensui, but he charges into battle anyway, asking Sensui to at least take his life with flash. Yusuke lands a kick and then hits Sensui with a barrage of punches, only for him to move out of the way, still unfazed. Meanwhile, Kuwabara uses his Dimensional Sword to break out of Itsuki's shadow dimension. Just as his friends escape, Sensui impales Yusuke with a single finger and kills him, sending Kuwabara and the others into a rage that jump their powers from B Class to A Class immediately.
Hiei unleashes the Dragon of the Darkness Flame and Kurama transforms into his former self. Hiei's dragon pushes Sensui through the portal Itsuki opened. However, in the pseudo-space, Sensui's sacred energy passes through the kekkai barrier. Hiei and Kurama, being A class demons, are unable to pass. In order to fight the former spirit detective, Kuwabara uses the Dimensional Sword to cut the barrier, fitting right into Sensui's plan.
They break through the kekkai and arrive in Demon World, where Sensui transforms into his first battle armor, forcing Hiei to put all his strength in the Dragon of the Darkness Flame and absorb it to further increase his power. Hiei, Kurama, and Kuwabara then unleash their most powerful attacks, but Sensui dodges and counters with kicks before using Kurama's rose whip to throw Kurama away from him, then subduing Hiei with another kick.
With all of them defeated, Yusuke comes through the barrier, riding on Pu with Koenma. Sensui senses great demon energy radiating from his body, and is amused by the fact that a demon hunter has become the demon. Hiei and Kurama attempt to stop Yusuke from fighting (insisting they each have one-on-ones with Sensui instead), but he confronts Sensui himself.
The two clash energies, then proceed to melee fight, with Sensui gaining the upper hand. Yusuke fires a spirit gun, but it harmlessly curves from the target. However, Sensui realizes that if it hit home, he'd have been beaten. So Sensui dons a second armor, switching his strategy from defense to offense. As he and Yusuke fight, all of Sensui's personalities begin conversing. The energy they release cause demons to join their fight, forcing Sensui to slay them once more.
After the two decide to change locations, Yusuke starts to catch up and begins fighting on par with Sensui, neither able to push each other back. Sensui manages to kick Yusuke a good distance, and Yusuke attempts to hide. However, his demon energy gives his location away and they carry on with the fight. Suddenly, Raizen takes over Yusuke's body and changes his appearance, as well as his power. Sensui is easily overpowered, bleeding from a punch to the face, and being pummeled to the point that his armor was failing. Raizen shoots a Spirit Gun, just as Yusuke begins to regain control. Yusuke urges Sensui to move, but Sensui suffers a fatal blow from the blast.
While Yusuke had ignorantly desired that his opponent be treated, Itsuki then reveals that he was to die in half a month anyway. Sensui tells the group that the apocalypse was never his true intention, it was to be killed by a demon to make amends with all the demons he had so naively killed without any thought of the consequences. In his dying breath he thanks Yusuke and felt for the first time, that he enjoyed his fight. After his death soon after, Itsuki honors his dying wish to not be judged by the spirit realm takes his body away to a pseudo-space for them to be alone for all eternity.
Sensui is last seen in a flashback from his younger years prior to his mission with his partner Itsuki when his predecessor, Kuroko Sanada finally retires from being a spirit detective as they are not looking at each other while they are walking away as Kuroko mentions to Yusuke about him and his different personality.
Powers and Abilities
Sensui was a very powerful human, noted himself to have more than ten times the spiritual energy than Yusuke in their fight. When Sensui started releasing his Sacred Energy, Hiei mentions that if Sensui was a demon, his energy levels would have been S-class, even though he was still suppressing his true power and openly saying that he was using less than half. Sensui's power was so great, that he held a distinct advantage over Yusuke, even in his demon form. According to Raizen, Yusuke's demon ancestor and the most powerful of the Three Kings, Sensui would've eventually killed Yusuke had he not interfered, despite that Yusuke had been revived as a mazoku. Additionally, it should be noted that these judgments of Sensui's power were made at a time during which he was so ill that he was judged to have about two weeks left to live. Sensui is also shown to have very sharp senses. Despite Sensui having more than enough power to overwhelm Yusuke, Sensui's instincts were hesitant to do so. It was revealed the reason behind Sensui's hesitation was because his instincts sensed Yusuke's dormant demon blood and knew killing Yusuke would trigger his rebirth.
Resshūken (裂蹴拳, literally translated as Fissure Kick Fist; VIZ; Lightning Kickboxing): An elegant fighting style that is only available to fighters that have mastered all other forms of martial arts. This style is considered to be the strongest, most elegant, school of martial arts in existence and relies on fast footwork in order to focus on fending off enemy attacks with the arms and using the legs to counterattack with powerful kicks. Genkai was the one to identify and name this fighting style during the first confrontation between Sensui and Yusuke. The English dubs pronounce this as "Reshuyuken." As a result of his training for this martial art, his physique is extremely well developed, to the point where Yusuke compared hitting him to punching a tractor tire. At one point, after punching Sensui repeatedly in the stomach, Yusuke had to take a somewhat comical time-out while Sensui was down to nurse his battered hand.
- By adding Spirit Energy to this style, Sensui created a new fighting style that he calls Reikō Resshūken (霊光裂蹴拳, literally translated as Spirit Light Fissure Kick Fist), which Kurama describes as "energy and style as one". Reiko Resshuken often involves him creating orbs of spirit energy with his hands, which he then kicks toward the opponent, enhancing their offensive force. The English dubs pronounces this as "Rayko Reshuyuken."
- As Kazuya, Sensui fights in a more brutal, sadistic manner.
- As the origional Sensui, his fighting style completely changes once he activates his Sacred Energy, because the style depends on which type of armor he has activated: the ultimate defense or the ultimate offense.
- Resshū Kō Kyū Ha (裂蹴紅球波, literally translated as Fissure Kick Crimson Ball Wave): This technique was Sensui's unusual variation of the Spirit Gun. He generated a ball of Spirit Energy, one strong enough to, at the very least, demolish an apartment suite, in one hand before kicking it. During his career as a Spirit Detective, this attack (or something virtually identical) appeared to be one of his primary methods of killing demons. Sensui is also capable of controlling the movement of this energy with his mind, making it float around at whatever speeds and directions he chooses. He is also capable of firing this attack without kicking it by simply directing the palm of his hand at a target and manifesting the energy orb. The orb will then fly in the direction of his palm. Presumably, this way of firing the technique is less effective than kicking it. As a Spirit Detective, before he mastered the Resshūken style, he would often throw the orb at foes rather than kicking it. This attack was strong enough to completely neutralize Yusuke's Spirit Gun despite being a fraction of the Spirit Gun's size.
- Splinter Resshūken (裂蹴紫炎弾, Resshū Shiendan, literally translated as Fissure Kick Violet Blaze Shots): Generating a field of energy that coalesces into a minefield of tiny energy spheres, Sensui then coalesces the balls into a powerful single energy sphere that he then kicks to his opponent. The scatter shot effect of this technique effectively ensures that the opponent gets hit at least once or more, and appears to display homing capabilities.
- Sacred Energy (聖光気, Sei Kō Ki, literally translated as Saint Light Energy): A special type of energy that is said to be the purest and most powerful kind, which Koenma calls the highest echelon of power. He also said that achieving the use of this type of power takes at least forty years of discipline and grueling training. In the Japanese dub and the manga, Shinobu stated he is the only one of the seven personalities that can use Sacred Energy because of his talents that make him stand out from others and that he awakened it on his own without any help from his other personalities. In addition, Shinobu stated that of the seven personalities, only he can use Seikoki, which makes him the most powerful out of the seven. It also implies awakening Seikoki requires a certain mental state since all the seven personalities would have access to the same physical powers Shinobi's physical body has.
- It is from this mastery of spiritual power, that Sensui derives his code name. By wrapping himself in it, Sensui is even able to fly and shield himself from any kind of damage dealt from most, if not all, A-class fighters, as seen when Hiei uses the Dragon of the Darkness Flame on him and all it did was push Sensui before burning out in pseudo-space. Channeling the energy seems to improve his physical capabilities as well, granting him improved strength, speed, and durability.
- Sacred Energy Armor (気鋼闘衣 , Ki Kō Tō I, literally translated as Energy Steel Combat Cloth): Surrounding his body with Sacred Energy, Sensui can create two forms of battle armor: one for much greater defense, the other for much greater offense. While using the first suit of armor, Sensui was able to dominate Hiei, Kurama and Kuwabara (after their powers had equaled that of A-class demons), as well as defend against Hiei's Sword of the Darkness Flame and Kurama's Rose Whip. Despite all that, Sensui's Sacred Energy Armor was not strong enough to defend against the newly-revived Yusuke's supercharged Spirit Gun.
- Switching to his Offensive Armor, Sensui increased his physical attack abilities to the point where the shockwave from a single punch could destroy an entire mesa in Demon World from a great distance away. This form was capable of maintaining a clear advantage in battle against Yusuke in his Mazoku Demon Form until Raizen took control of Yusuke.
- Energy Projection Sensui is capable of utilizing his Sacred Energy aura as a physical force. Simply by increasing it's intensity, he can project it outward in at least two ways; as a phenomenon similar to a very strong wind, or as a series of blasts that manifest as blunt-force strikes to a target.
- Twisted Twister (裂破風陣拳, Reppa Fūjin Ken, literally translated as Fissure Break Wind Encampment Fist) or Aura Vortex: Sensui first spins around extremely fast and creates a strong tornado. The tornado then engulfs his opponent. Inside the tornado, the wind slices his opponent like a sharp knife. This technique is very similar to Jin's Tornado Fist Explosion/an offensive version of the Wind Barrier.
- Energy Gun (気硬銃, Ki Kō Jū, literally translated as Energy Hardening Gun): Never really named in the anime, both Japanese or English, this weapon is unique to the Sensui personality called Kazuya, the bloodthirsty killer created in the aftermath of the Feast of Human Vices that Sensui stumbled upon. When Kazuya comes out to play, Sensui's right hand is replaced with a gun barrel that automatically hardens Spirit Energy into the shape of a bullet. In the manga, this barrel simply protrudes from a cauterized stump, while in the anime it emerges from a gunmetal mount that covers the stump of the right hand. This ability was never used for anything more than a single surprise attack and torturing Yusuke, as Kazuya was a fairly poor fighter despite his sadism and brutality.
- Sacred Energy Beam: Unnamed anime-only technique that fires a Sacred Energy blast. Capable of eradicating hundreds of low-level demons in a single sweeping discharge.
- Sensui and his successor Yusuke are complete opposites in every possible sense, from their viewpoints to their actions. While Sensui treated his job as an honor, Yusuke saw it as more of a chore. Sensui is refined, polite, calm, and hardworking, whereas Yusuke is hotheaded, foulmouthed, lazy, and shows little to no respect for authority figures. Similarly, their fighting styles are different; where Sensui uses the elegant martial arts style of Resshūken that revolves around kicks and mostly deflects and counters his opponent's attacks, Yusuke uses a brash and unrefined street-fighting style centered around punches and prefers to charge forward and pummel his enemies. In the end, even their species differed, with Yusuke becoming a demon hybrid and Sensui dying a human.
- These differences were in fact one of the primary reasons why Koenma decided to hire Yusuke to be Sensui's successor as Spirit Detective; after witnessing the problems that Sensui's dedication, intelligence, philosophical musings and inability to cope with shades of grey had ultimately caused him, Koenma decided that someone less intellectually and morally developed along with having less dedication might have an easier time coping with the potential encounters that would challenge their school of thought while on the job. In Koenma's own words, after what happened with Sensui, he "wanted someone who wouldn't think too much". Notably, when Yusuke and Kuwabara witnessed the tortures that Gonzo Tarukane (a human) was inflicting on Yukina (a demon) for his own petty reasons, they were able to take in the knowledge without having their beliefs turned upside down unlike what happened to Sensui and the events surrounding his breakdown.
- While Kamiya (Wrath), Makihara (Gluttony), Hagiri (Pride), Mitarai (Envy), Amanuma (Sloth), Itsuki (Lust) and Elder Toguro (Greed) represent the seven deadly sins of Catholicism, the true Sensui (excluding Kazuya (Wrath), Naru the female personality (Lust) and Minoru (Pride), is devoid of any true sin, like a fallen angel who still upholds his duties even if they are warped from his original goals. Hence, his Black Angel title.
- His seven personalities may be a reference to the seven-headed Beast of Revelation.
- Sensui has seven points of hair on his forehead, and his Offense armor has seven spikes around the shoulders.
- Concerning his death, there are differences surrounding it in the manga and anime:
- In the manga, when Koenma asks Sensui why he’s been so obsessed with making a portal to Demon World, he explains that he simply wanted to come here. After learning that the human race which he had fought to protect up until then was nothing but scum, he began to loathe having the same blood as them flowing inside him. He wanted to be reborn in the Demon World, and get there by any possible means. The portal itself was just a gift to the demons; his real goal was simply to die in Demon World, and he’s glad he got to do it. He thanks Yusuke for making him enjoy fighting for just a brief moment and then says that he’s certain he’ll be reborn as a demon this time. He then passes.
- In the anime however, he explains that Demon World is the home of the demons, so when he started having doubts about his simplistic black-and-white world view, he started wondering what had happened to all those demons he had killed without even thinking about it. He started to want to come to Demon World at all costs, and is glad he was able to see their home world. His true goal was to die in the Demon World and be killed by a demon, though he knows that this won’t really help the demons he killed to rest in peace. He thanks Yusuke for making him enjoy fighting for just a brief moment, then dies without saying anything else.
- Besides changing Sensui’s motivation from wanting to be reborn as a demon to wanting to die by a demon’s hand, the anime leaves a little part of Sensui’s death speech out. In the manga, when describing his past, Sensui says that as a kid he soon “got used to the blood on his clothes nobody else could see” (from fighting demons) and believed the world was comprised of good and evil, even thinking that wars always involved a good country fighting an evil one.
- When Itsuki comes forward to take Sensui’s dead body away, in the anime he says that Sensui’s desire was to be killed by the strongest demon in the Demon World, which turned out to be the reborn Yusuke, which must have made him happy. Itsuki goes on, saying that in the end Shinobu overcame the different personalities he created to deal with his internal contradictions, becoming the pure Shinobu he once was, and perhaps his soul has been partially saved.
- Its heavily implied Sensui's soul still resides in his body, unwilling to leave; as he did not wish to go to Spirit World, its likely Itsuki will keep his body preserved to prevent his soul from leaving.
- In the Filipino Dub, Kuwabara's voice actor, Neil Yu's voice for Shinobu Sensui had a sinister deep pitch during the Chapter Black saga as Kazuya, one of Sensui's seven personalites which resembles Kuwabara's voice with a manner of speaking kanto or a squatter accent. He later adapts it to his main voice role as Nakago in the manga and anime series Fushigi Yuugi.
- The Minoru personality mentions he could feel "the rot" setting in his body. Whether this was a metaphor for his illness or was used as inspiration for it is up for debate.
- Yu Yu Hakusho manga; Chapter 152
|e v||Spirit Detective|
|Members:||Yusuke Urameshi | Shinobu Sensui | Kuroko Sanada|
|e v||Sensui Seven|
|Members:||Shinobu Sensui | Itsuki | Kaname Hagiri | Minoru Kamiya | Kiyoshi Mitarai | Tsukihito Amanuma | Sadao Makihara | Elder Toguro|