Hantengu takes on the appearance of a short frail man with a very thin and skeletal body, covered with veins and wrinkles and is usually seen crouching. His most noticeable feature is a large bump on the top of his head, accompanied by two curved horns.
His face is thin with a sharp chin and constantly wears an expression of terror and fear, with a prominent brow ridge that lacks eyebrows. His eyes are narrow and often appear to be squinting, lacking any visible pupils.
He has dark shoulder length wavy hair with a low hairline, only growing out from the back of his head and ears, who themselves are sharper and longer then a normal humans.
His nails are long but not sharp like most other demons and retain their natural square form.
Clothing wise he wears a dark kimono that is split in the middle, the right half being covered in a pattern of flowers and lines with the left half being dark and lacking any detailed features.He also wears dark pants and sandals.
Hantengu's primary form had a persona of cowardice. He was easily frightened by what occurred in his surroundings, showing traits of paranoia, fear and delusion, as, despite the obvious evidence of his numerous crimes as a human, he still believed that he was innocent and didn't do anything wrong. Even as a Demon, killing and eating scores of innocent people, he still stubbornly and delusionally believed that he was innocent. The more threatened he felt, the stronger his other personalities became.
Sekido (積怒,Anger?) - The personification of Hantengu's anger. As such, this clone portrayed himself to be in a constant state of anger, irritation and hatefulness, even towards his fellow clones, which could be seen when he forcibly absorbed them against their will to form Zohakuten. He also showed himself to be the most dominant of the emotion clones and appeared to be the leader, as he was the one who barked orders to them when they were battling the Demon Slayers.
Karaku (可楽,Relaxed?) - True to his name, this clone showcased himself to be the most relaxed and laid back of Hantengu's clones. The entire time he was battling against Genya Shinazugawa, Tanjiro Kamado and Nezuko Kamado, he was constantly praising them and, instead of taking the battle seriously, he instead saw it as nothing more than a game, seeming to only take interest in the new experiences he was obtaining from the battle. This could be seen when he happily expressed his interest at the new sensation upon being shot by Genya and commenting that was the first time he was ever injured in such a manner. This was demonstrated again, only this time during his battle with Nezuko, when, instead of finishing her off, he decided to tease and play with her despite being able to easily overpower her anytime he wanted. This behavior easily got on the nerves of his fellow clones, specifically to Sekido, who constantly berated him for taking so long in battle.
Aizetsu (哀絶,Sorrow?) - This clone portrayed himself to be completely dejected, sour and negative as he constantly described everything as being depressing. Out of all the emotion clones, Aizetsu was shown to be the most calm and collected out of all five of them, as seen where instead of frivolously wasting time on entertainment as Urogi and Karaku or immediately getting agitated and enraged by anything like Sekido, Aizetsu was shown to calmly analyze his opponents and think out his strategy and figure out his opponents abilities and weaknesses before attacking.
Urogi (空喜,Delight?) - The most jovial and giddy of Hantengu's clones. Similarly to Karaku, he seemed to view the entire battle against the Demon Slayers as nothing more than a game or as a source of entertainment, as seen when he happily complemented Tanjiro on his intelligence for correctly guessing that neither one of the four clones were the "real" body, and constantly exclaimed that the entire fight against Tanjiro was delightful.
Zohakuten (憎珀天,Hate?) - The evolved form of Sekido after he absorbed the other clones. Zohakuten has displayed the same traits of Sekido, as he too was easy to enrage and was incredibly spiteful and hateful towards his enemies due to him, deeming them as "evil" for bullying his "weak and innocent" self. Like Sekido, he was also incredibly foul-mouthed as seen when he constantly insulted his opponents and referred to Mitsuri as a harlot, constantly calling her various degrading names in his thoughts. He also seemed to harbor an immense sense of loyalty towards Muzan, as seen when he told Mitsuri that he only heeds and follows the orders of one man in the entire world. Out of all the clones, he was shown to be the most intelligent and insightful aside from Sekido, as seen when he easily analyzed why Mitsuri Kanroji survived his powerful attacks and figured out the true source of her strength.
Urami (恨み,Resentment?) - The final of Hantengu's clones, and his last-ditch attempt at surviving. He was shown to be just as hypocritical and delusional as Zohakuten and Hantengu, as he angrily told Tanjiro not to bully and hurt his "weak and innocent" self. He angrily asked why Tanjiro couldn't "see" his innocence and, true to his name, he has shown to be the embodiment of Hantengu's resentment due him to being punished and persecuted for crimes that he was "innocent" of.
Abilities and Powers
Having held the position of Upper Rank 4, Hantengu can be considered to have been the fifth strongest Demon in the series.
Stealth Master: Hantengu's skill in stealth seems to be his most formidable ability when not divided into his clones as can be seen when he managed to easily infiltrate the blacksmith village of the Demon Slayer Corps, one of their most vital and well fortified bases, without any of the numerous guards noticing. Later on he managed to sneak up on both Muichiro and Tanjiro without them noticing, despite the former being a Hashira and having prodigal skill and talent in battling demons and the latter's superhuman sense of smell.
Blood Demon Art (血鬼術,Kekkijutsu?): Hantengu can split apart into several younger looking forms, each with their own personalities and powers created from various facets and emotions of Hantengu. Each is identified by their clothing and a kanji tattoo in their tongue labeling their core emotion.
Main form of Upper Moon 4 which is a diminutive version of the original body and also the body possessing Hantengu's "core." This body has incredible physical fortification and durability, that not even Genya's Sun Steel bullets or sword could penetrate his flesh, despite Genya using his demon enhanced strength to further strengthen his attacks.
One of the first emotion clones shown by Hantengu, his main form of offense is his ability to conjure powerful lightning and thunder attacks using a Khakkhara (錫杖,Shakujō?) staff created from his own cells. The lightning attacks themselves are powerful enough to nearly kill fellow demons, as seen with Nezuko, and to completely paralyze demon slayers. However a weakness to this is that Sekido cannot electrocute something created from his own cells as seen when he could not channel his lightning through the severed leg of Urogi. When angered and enraged enough Sekido can forcibly absorb and assimilate his fellow emotion clones and form Zohakuten.
Flesh Staff: When Sekido left his Staff impaled in Nezuko to continue shocking her with lightning, Sekido displayed the ability to grow a new Staff from the palm of his hand using his own flesh and bone, showing that Sekido can create more than one staff for battle.
The second of the emotion clones created by Hantengu. This clone has the power to create a maple leaf like fan using his own cells. He can use it to create powerful gushes of wind capable of easily leveling an entire building and nearly crushing humans and demons respectively to death and leave behind maple leaf like craters. A weakness to this fan is that other people can make use of it once taken from Karaku.
Flesh Fan: When Karaku's arm was torn off and seperated from him by Nezuko and was blown away by his own technique, Karaku showed that he could easily regrow and create a new fan from his flesh similar to Sekido.
The third emotion clone created by Hantengu. This clone possess the ability to fashion a long spear Yari from his cells, that can then extend and shrink according to Aizetsu's will. He incorporates this ability in close range combat by extending the reach of the spear during mid thrust and slash, allowing him to easily butcher his opponents from a long to mid range combat.
Flesh Spear: Like Sekido and Karaku, Aizetsu's spear is also likely created from his own flesh and bone and thus explaining its ability to grow and shrink at will.
The fourth emotion clone created by Hantengu. It takes the form of a gleeful harpy-like demon with wings and bird talons with power to blast sonic screams from his mouth as his main attack and uses his claws and talons as his secondary weapons. Urogi's claws were also stated to be sharp enough to cut right through diamond
Flesh Detachments:This clone is also capable of creating several miniature clones of himself from his severed body parts. The clone is also capable of firing sonic screams, however only possess less than a tenth of their original power allowing even the weakest demon slayer to easily shrug its attacks off.
The most powerful emotion clone of Hantengu formed by Sekido's absorption of Karaku, Aizetsu, and Urogi. This clone can conjure wooden dragons to attack his opponents by beating on the five drums attached to his back to control the dragons. The Dragon heads are capable of breathing out the attacks and powers of the other absorbed clones as seen when the heads breathed the lightning and thunder of Sekido, emitted the Sonic Screams of Urogi, generate powerful wind attacks that leave behind gigantic maple leaf craters like Karaku, and breath out spear-like thrust attacks like Aizetsu. Zouhakuten has also demonstrated the ability to use own unique Blood Demon Arts.
Countless Striking Trees (無間業樹,Muken Gōju?): Zohakuten unleashes his dragon-like trees towards the enemy, making them rapidly grow bigger and multiply as they rush towards his opponent.
Crazed Cry of Thunder Death (狂鳴雷殺,Kyōmei Rai satsu?): An attack utilized by Zohakuten's wooden dragons, which demonstrate the ability to combine the unique powers of Urogi and Sekido's powers to create an attack of thunder and sound.
Compressed Sound Waves (狂圧鳴波,Kyōatsu Meiha?): Zohakuten emits wavelike-screams — similar to Urogi — which are powerful enough to destroy a human's body; For stronger individuals, the attack can temporarily stun the opponent as seen when he attacked the Love Hashira, Mitsuri Kanroji.
The final emotion body detachment created by Hantengu as a last line of defense, being essentially a larger more physically powerful version of his "core" with its primary purpose is being a living armor used to hide Hantengu's true body inside its heart.