Akaza

Akaza was a very muscular young man of average height with skin so fair, it appears bright green-tinged white, decorated by a pattern of thick blue lines, which resemble the criminal tattoos he had as a human. Akaza had short, bright pink hair that fluffed out around his head, and inward-tilting yellow eyes with pink eyelashes and blue sclera that looked somewhat like cracked glass. The kanji for "Upper Rank" (上じょう弦げん, Jōgen?) and the daiji for "Three" (参さん, San?) are etched into his irises as well. The lines on his face curved through each of his eyes from below his ears to over his temples, another blue line running from the center of his hairline to the bridge of his nose, with two more lines running around his neck, three others branching off the lower one to his torso. The middle line runs directly down his chest to halfway down his stomach, and the other two branched off to the sides over each side of his chest to join the two other lines, this same three-line pattern there also repeating around his waist. On his arms, there are lines running down the front of his shoulders that run into two more, which go around his biceps, before continuing to run down to his wrists, below which it could be seen that each of his fingers are also dark blue with an orange fingernail, his toes also sharing this unusual appearance. Akaza wore little, only sporting a short, sleeveless dark purple-pink haori that was cut off at his waist, left open to expose his chest, that was decorated by a square pattern on his back. Below this, he sported a pair of baggy white pants that he rolled to just below the knee with a blue rope belt to secure them at his waist. Akaza prefers to go barefoot, but wears a chain of large round pink pearls around each of his ankles.

Akaza is a headstrong, stubborn and battle-crazed Social Darwinist who enjoys fighting, especially against strong Demon Slayers. He purposefully drew out fights so as to savor every moment of it, always complimenting his opponents when they unleash strong techniques or land blows on him, usually remarking that their techniques and swordsmanship are magnificent and intriguing. Akaza looked down on anybody he deemed weak, so much so that his skin would crawl at the sight of them. He genuinely respected those who were strong in his eyes, demanding to know their names, and would not stop until he finds out; he remembers all the names of strong past opponents and committed them to memory as tribute to their strength. Akaza also presents an opportunity for those he recognizes the strength of to become demons, believing that preserving their refined techniques and skill was right and feels pain watching the deterioration of those blessed with extraordinary gifts as they age, and going so far as to kill them in order to preserve their magnificent skill himself should they decline his offer to become a demon. Akaza also doesn't discriminate strong warriors that were weak before, as shown when he praised and complimented Tanjiro Kamado despite initially attempting to kill him over how weak he was during their first encounter, even going so far as to thank Kyojuro for Tanjiro's growth. Akaza believes strongly in Social Darwinism, believing that the law of nature dictates that all weaklings shall be eliminated.

Akaza has a deeply-rooted psychological need to become stronger, and did not get along with his fellow Upper Ranks, seeing them as his rivals. He is especially antagonistic towards and somewhat jealous of the two Upper Ranks above him, Doma and Kokushibo, lashing out at Doma and vowing to kill Kokushibo.[10] Even after being beheaded during his fight against Tanjiro and Giyu Tomioka, he stubbornly held on and continued to fight, remarking that he must become the strongest no matter what, to the point of overcoming all demons' shared weakness of decapitation by Nichirin Swords through nothing but sheer willpower and resolve. It was later revealed that Akaza's desperate and stubborn pursuit of strength was to heal his sick father and to protect the ones he loved and cared about, namely his fiancée Koyuki and his teacher Keizo.