Villains

Toguro Ani - one of the most gruesome character ever created in anime.  He uses body weaponry.  He can manipulate his appendages into anything he wants.  He is also immortal.  Like his brother Ottoto, he sold his soul to gain power and immortality.  Because of this immortality, he can take more punishment than other fighters.  He enjoys playing around with his enemies rather than defeating them. He met his end at the hands of Kurama.  While they were fighting, Kurama slipped a seed into him.  The result was Toguro Ani became trapped and became part of Kurama's Evil Tree Hallucination.  Due to his immortality, he will forever be bombarded with hallucinations.  

Toguro Ottoto - younger brother of T. Ani.  He mainly uses brute strength and powerful energy.  He looks like Arnold S. in the Terminator.  Long ago, he was a human fighter and fought along side Genkai.  They were a force to be reckoned with.  They became qualifiers on the Black Martial Arts Tournaments.  There, they battled a warrior named Kairen.  Kairen killed many of Toguro's friends during the tournament.  With the help of Genkai, Ottoto beat Kairen. For winning the tournament, they offered to make a wish.  Genkai wanted to move on and train.  However, Toguro never shared her views.  He made a wish that he would train in the demon world and become stronger.  With that desire, their partnership dissolved.  He developed a taste for power.  He and his older brother Ani offered their souls to a powerful demon and granted them more power.  

Itsuki - the only demonic planeswalker in the demon world.  He uses the hands from the Shadow World to destroy his enemies.  He also has a pet that swallows his enemies and keeps them in his dimension.  Before forming an alliance with Sensui, he was a demon fighter that accidentally stumbled upon Ningenkai.  He had no desires to kill any humans.  He trained himself to master the human martial arts.  He only resided on forests for he feared that he might be a target of humans. Koenma ordered Sensui, back in his spirtual detective days, to kill Itsuki because he was too powerful for the Human World.  When Sensui defeated him, he gave Itsuki his last words.  Itsuki said that he wanted to watch his favorite TV show for the last time.  Sensui became amused with that response.  It was Sensui's favorite TV show too.  He spared him because he thought that he might be valuable to him.  From that day on, they became an unbeatable team when it comes to hunting demonic fugitives.

Sensui - the former spiritual detective.  One of the most mysterious villains in YYH.  Even as a child, he showed great potentials and this attracted evil spirits who would want to use him as a tool for evil.  To protect him, Koenma invited him to a spiritual detective.  When he grew strong, he desired nothing but to destroy the demons. He became a renegade when he was corrupted by a mysterious organization composed of wealthy gamblers.  They planned to corrupt him by showing the "Black Tape" which depicted humans torturing poor innocent demons.  When he got his hands on the tape and watched it, he realized that he was on the wrong side and developed a lust for spilling human blood.  He disappeared for ten years and when he came back, he brought 6 other teammates.  He planned to open a gateway to the Netherworld and end the existence of man. He has seven personalities living inside him.  He gained them through the spirit world.  He bargained with them and offered them a chance to fight again through him.  One of his personalities is a female and a blood thirsty fighter.  One of the most powerful villains in YYH. 

Hagiri (aka. Sniper) - one of Sensui's lackeys.  He uses the element of speed to kill his enemies.  He can turn ordinary things like coins and dices into moving bullets.  He can also put trace marks on the opponent's pressure points and hit it.

Karasu - his name means "crow".  He is an expert in gunpowder .  He manipulates them and turn them in living weapons of mass destruction.  He is believed to be faster than Hiei.  His mask serve a purpose.  It protects himself and the crowd.  When it is removed, he absorbs all combustible particles in the air and his hair turns golden yellow (like a super saiyan) and he is in super mode.

Yakumo - King of the Netherworld.  He appeared only on the second movie.  Long time ago, Reikai and Meikai waged a war that lasted for a long time.  Enma Daiou finally defeated Yakumo and his cohorts and sent them to the depths of space.  However, Yakumo escaped his confinement through the collection of evil souls that Reikai couldn't handle.  To wage to his vengence, he created a very powerful flood that submerged Reikai.  Next on his agenda was to retrieve the power sphere that gives Meikai its power.  To do this, he must destroy the elemental sites on Ningenkai to prevent the resurrection of Reikai and establish Ningenkai as the new Meikai because the previous one was destroyed by Enma Daiou.  When he learned that one girl survived when Reikai was submerged, he hunted the girl and captured her.  The girl was Botan and she hid the sphere inside of her, ordered by Koenma, so no one can get it, however, it proved to be powerful to be hidden.  Yakumo finally got the power sphere and used it to revitalize his powers.  Yusuke, in the end, used the power of the sphere against him by converting it into spiritual energy and shared it with the rest of the YYH gang.