How they compare: Shinobu Sensui (Yu Yu Hakusho)

Once there was a boy with an extreme spiritual aura, and so he was contracted by spirit world to act as a defender of the human world against the demon world as a spirit detective. He gladly accepted, for the boy sought to be a champion of righteousness. He was intelligent and determined in addition to talented with his sole fault being an inability to see the world outside of a white and black perspective. He defeated the demons easily, often brutally murdering them for they were evil demons. However after meeting and partnering with his demonic partner Itsuki, Sensui began to internally break down upon realizing the creatures he had been brutally murdering had been complex people and not just monsters. Though he refused to show his feelings to anyone, and was described by Itsuki as always having his head filled with many thoughts to simply keep sane.

This would all change upon witnessing the "feast of human vices", a horrific ritual where humans tortured helpless demons for no reason but their sadistic pleasure. At witnessing this, Sensui's mind broke at seeing the true depths of depravity man could be capable off and he in a rage murdered all the humans present. To protect his psyche, Sensui's mind split off into another personality, the murderous Kayuza who he placed all the guilt within. 

Sensui was disbanded as a spirit detective but at this point it was far too late. Sensui became more and more fixiated on the evils of humanity, until coming to despite them as a far worse blight then the demons, for the demons were honest in their evil and humans hid their evil behind a veneer of civility and pretension. Sensui stroke out to bring about the end of humanity at the hands of demon-kind, along the way developing a full six alternate personalities, including Kayuza, to aid him.

 

For a human, Sensui was unprecedently powerful, actually reaching the level of the S-Class Demons. For comparison the King of Spirit World who can cause volcanic eruptions with his power is only A Class, and Yusuke when he could destroy countries was also A class. S class was a level Spirit World could not handle, and true to it's title, even a team of A Class Fighters could not defeat Sensui in combat. Sensui also has perhaps the most feat of the YYH Strongest characters

Just his presence was causing a stress on the human world (Earth), and he claimed he could not use more then 50% of his power or it would put too much stress on the planet. Interpretations of this feat vary from roughly teraton level to potentially planet level. While I take the conservative value, it's notable this was a feat of Sensui's raw power while he was holding back, meaning it is also very casual.

Sensui was also fast enough to move comparable to a spirit gun from Yusuke that traveled to a distant mountain in the time it took Yusuke to fall a little bit which was calculated at ~mach 104. However this is a lowball, as Yusuke's spirit gun was calced during the Dark Tournament much earlier to be somewhere in the range from Mach 153 to Mach 433 making Sensui consistently to be massively hypersonic. 

  

Sensui is a user of spirit energy, or "Yoki". Users of Yoki in combat can create blasts or auras of yoki, enhanced their physical stats, see invisible enemies, and hit intangible enemies (not only can they affect demons, but Yusuke is implied to be able to destroy the soul and Hiei and Younger Toguro have erased evil spirits with their auras). Yoki's energy projection is strong enough that Yoki users can knock back weaker beings simply by opening their eyes or melt them with their sheer presence. That said, not being a demon, Sensui is neither invisible nor intangible himself. 

Yoki also gives access to minor psychic abilities including a precognitive ability that allows even low level users of Yoki to win against a computer at rock paper scissors 2/3rds of the time, the ability to sense enemies in the dark and to sense danger. Yoki also allows for some level of manipulation of the elements. Low Level Yoki users have created a smoke screen or disappitated a fire, with Sensui himself creating giant tornados from his fight and causing a massive earthquake with his presence. Sensui also possess the technique to summon a targeted tornado to envelop a target who winds cut like knives (Reppa Fuujin Ken)

Sensui also was able to attain enlightenment and the ability to use the most purified form of energy known as sacred energy. Sacred energy as the most pure form of energy can boost Sensui's power further and allow him flight and the abiltiy to create matter from nothing, most notablly his armors, which he used to drastically boost his offense or defense. Normally attainment of sacred energy requires 40 years of dedicated training but Sensui was able to attain it in only 6 years by focusing all 7 of his personalities on the task.  

Sensui's most dangerous assest is arguably his sheer combat skill, to the point I think he's arguably one of the most skilled characters in shonen. Sensui knows the martial art known as Resshuken, a perfectly elegant martial art considered the strongest of all, for it can ONLY be learned by learning every single other martial art in existence. Sensui was so skilled that he formed his own form of the Resshuken by mixing it with his energies called Reiko Resshuken. His different personalities have their own forms of this martial art, including Kayuza turning his own arm into a gun and firing spirit energy with it.

Sensui's skill is so great he can learn new skills incredibly quick due to being able to train 7 times faster and was so great that only minutes after learning of a person can predict all their movements and counter them.

Rivaling Sensui's skill for his most dangerous assest is his cunning intelligence. Literally all of Sensui's plans, up to and including his plan to murder the protagonist succeeded save for being thwarted by the completely unpredictable intercession of one of the Three Kings of the Demon Worlds. He is an expert manipulator, having manipulated the spirit world and human world authorites to set the stage for the opening of a portal to demon world to allow the demons to destroy the human world. 

In terms of weaknesses, Sensui was actually dying of a terminal disease by the time of his fight with Yusuke and would have died in a month. This means that aging and disease powers should be fairly strong against him. He also has a code of honor, if warped by his insanity, as he allowed Yusuke's companions to fight him to try and avenge him. This is likely related to his distaste towards killing non-humans. In fact it is implied that destruction of humanity was secondary and his real primary goal subcounciously was to die at the hands of a demon to repent for his awful deeds towards them. That said this shouldn't be exaggerated, he wouldn't just let a demon kill him; as he still beat up Kurama and Hiei who are both demons.

Name: Shinou Sensui, Sensui, Black Angel

Origin: Yu Yu Hakusho

Classification: Former Spirit Detective

Powers and Abilities: Enhanced Physical Capacities, Energy Projection, Superhuman Skill and Intellect, control of the elements, flight (sacred energy), creation (sacred energy), minor precognition, can see invisible entities, can hit intangible entities, Holy Energy Projection, can turn his arm into a gun arm, can switch between personalities as appropriate, can destroy signifigantly weaker entities with his presence

Weaknesses: Technically dying of a terminal disease, has a twisted sense of honor

Destructive Capacity: Country Level+

Range: Planetary

Speed: Massively Hypersonic

Durability: Country Level+

Stamina: Vastly superior to beings who can hold themselves up on one finger for 12 hours. Can likely fight for days

Standard Equipment: Nothing notable

Intelligence: Master of all martial arts, created his own form of the supreme martial art, genius manipulator, can predict all of someone movements minutes after meeting them

So how would Sensui do in other verses

In Marvel Comics, Sensui would be an ultimate form of stomp or be stomped fighter. Almost every street leveler, even if they can match him in speed and even if some of the most skilled can match or exceed his skill (like the likes of Taskmaster) would be melted by Sensui's sheer presence, especially as intangibility would not stop him. Most characters on his power tier like some Iron Man variants or Namor would have difficulty fighting him due to his sheer skill level though Iron Man can at least nullify his ability to quickly adapt since his software does the same with his opponents fight patterns. That said Sensui would likely be able to counter this simply by switching to a different personality who fights completely different. 

Sensui would be ranked as a Mid Meta Level entity though would stomp most Mid Metas and below and the ones he doesn't stomp would likely stomp him via some completely broken ability he doesn't have a counter too. The real danger is what happens if he starts learning the massively varied and often broken abilities of the Marvel Universe. 

Also just because the two happens to be in the same stat range, Sensui would be extremely powerful though not unstoppable in the MCU. Outside of the cosmic beings, the MCU Avengers generally get up to country level from Thor taking the energy of a neutron star and scaling to numerous MHS feats most notablly Thor's hammer leaving the atmosphere at over Mach 1,000. This means they would have the speed advantage but be at a power disadvantage, especially if Sensui uses his sacred energy armor. While Sensui would be a dangerous threat due to his skill and intellect, I think the MCU Avengers would be able to take him via numbers and versatility, especially given Doctor Strange's magic dimension hax.

In DC Comics, Sensui would be in a similar stomp or be stomped scenario. Most of the low tiers, even the very hax ones could not get close due to his aura's pressure though there are especially haxed ones that could win (like the likes of Cain, Jill Presto etc.) He would roughly be in the range of power of beings like Aquaman, Mera and the Weather Wizard, though outside of Aquaman I would be highly skeptical of any of those being able to defeat Sensui due to his sheer skill and intelligence. If he starts to learn the various superhuman martial arts or magical skills available in the DC Universe he would grow massively stronger and more haxed.

While Sensui would be incredibly skilled to the point that he would give Batman a run for his money, he wouldn't be able to stand against the sheer power of anything on the level of Kryptonians. That said against any metahuman on a lower scale then that, he would be extremely dangerous, being a strong combination of mental ability, and a supernatural power level on the scale of affecting a whole planet. 

The series people like to compare Yu Yu Hakusho to a lot to try and figure out equivalents in terms of power, DBZ. 

Near the end of the original Dragon Ball, Piccolo Jr. in his fight with Goku at the 23 world tournament, created an attack that razed a rather small continent (calced at about 4 trillion tons of tnt) at speeds around Mach 1,000. This means Goku at the end of original Dragon Ball and Piccolo at the end of original Dragon Ball would be faster then Sensui but would not be as strong as him, especially if he was amped on Spirit Energy. I believe this is appoximately where Sensui would fit in terms of fighting.

Sensui is vastly more intelligent then Goku and Piccolo though Goku is superhumanly skilled having learned techniques that require dozens of years just by seeing it, and with both having very exotic abilities to Sensui such as regeneration, elasticity, and homing ki attacks. Overall I think Sensui could compete with either end of DB Goku or Piccolo.

In the other big Battle Shonen Series of the 80s, Saint Seiya, Sensui would roughly be comparable to the Silver Saints in terms of power. The Silver Saints are generally country level and scale to lightning timing or above at max speeds, which would put them roughly comparable to Sensui's stats, if a bit slower on average. 

Sensui's skill and intelligence would exceed even most Silver Saints and while his ability to react and evolve in combat is not quite as good as a Saint's, Sensui could get around it by elegantly switching between his personalities with their own forms of fighting. That said Sensui could get caught by some of the more exotic abilities of the verse like Algol's Petrification. In Saint Seiya, Sensui would roughly be on the level of the Silver Saints, though if he learned of cosmo he could become even more dangerous very quickly by rapidly learning the skill of cosmos.

 

The other shonen compared to YYH a lot. The Espada in Bleach were able to destroy Los Noches, an area so large it would take 3 days to walk from one part to another part within it with one attack called Gran Rey Cero and the strongest of the Espada can destroy Las Noches just by transforming similar to how Sensui can damage the world with his spiritual power. That said Sensui would be slower then the verse, being slower then the Auswahlen Light which even Captains can more comparable too. Overall Sensui would likely be around Lower Espada Tier, being more powerful (around the level of Higher Espada) but slower being slower then even captains. That said he would be at serious disadvanage against their inter-dimensional movement as he required Itsuki to take him across dimensions. That said it's possibly his manipulative nature would serve him well in the verse, as it's been shown to be a strong strategy in verse, and the Espada in particular are prone to in-fighting especially when not under Aizen's direct control. It also helps that he would be able to see everyone given that Yoki users can see invisible entities.