Obanai Iguro

Obanai is short and slim with a toned frame and straight black hair of uneven length. His eyes show heterochromia, the right a yellow shade and the left teal, and his right side is nearly sightless. Bandages typically hide the bottom half of his face, masking the wide scars left when his relatives sliced his mouth open to resemble a snake's. His white snake Kaburamaru is almost always coiled around him. Severe and curt, he is intensely devoted yet prickly toward Tanjiro, and he bears a heavy burden of guilt and self-hatred from his childhood, convinced his corrupted blood denies him any chance at happiness.

The Iguro family amassed wealth by serving a serpent demon, handing over their infants in return for the riches taken from its prey. Being the first boy the family had produced in centuries and one bearing unusual eyes, Obanai was kept locked away, fattened up, and held in reserve, his mouth eventually cut to satisfy the demon. He broke free with a stolen hairpin, taking with him the snake that had crept into his cell, and was saved by Shinjuro Rengoku. His one surviving relative blamed him for the demon slaughtering the rest of the family, a blow that scarred him, and he became a slayer to release his rage.

Serving as Serpent Hashira, he sees the later campaigns through, attending Hashira gatherings, inspecting Yoshiwara after the Upper Six clash, and dropping into the Infinity Castle. In the climactic fight against Muzan he pushes himself to the edge of death, awakening his Mark and turning his blade bright red, wishing that in a peaceful next life he might tell Mitsuri how he feels.

Obanai ranks among the mightiest Hashira, using Serpent Breathing with an oddly curved Nichirin blade whose twisting, hard-to-predict strikes match his fighting style. Half-blind, he makes up for it with the senses he honed during his imprisonment and works in tight coordination with Kaburamaru. At the climax he awakens a Demon Slayer Mark and reddens his sword, driving his power to its height during the assault on Muzan.