Eso

Violet eyes set against darkened sclera mark Eso's face, paired with black hair (rendered brown in the animated version) and a set of slim brows that each carry two stud piercings. The animated adaptation tweaks several of these details, giving him deep red eyes, a ridge running down like a spine, and teeth that are narrower and more squared off. His muscular, towering frame is hard to miss.

The detail he most wants hidden sits on his back: a grotesque second face with hollowed sockets, an absent nose, and a gaping lipless mouth crowded with long fangs. To keep that growth from overheating, he settled on a deliberately exposing wardrobe, a striped collar finished with a bow tie, cuffs banding his wrists, and a chest strap anchoring suspenders that run down to a thong and leggings.

For Eso, his brothers are everything. He treats Choso, Kechizu, and himself as a single entity, a bond forged across more than 150 years spent cut off from the rest of the world. Outsiders barely register to him emotionally; he follows whatever his elder brother decides while keeping his younger brother safe. He holds no special hatred toward sorcerers, and before the clash he was even prepared to let Nobara walk away unharmed had she chosen to run.

Theatrical and fond of banter, he likes to strike dramatic poses and lord over those he fights. That sociable surface hides a raw nerve, though. The face on his back fills him with shame, and a single glance at it, even an accidental one, can send him into a murderous rage.

Eso carries a special grade ranking as a cursed object, brought into being by Mahito's faction to help curses seize control of Japan. He and Kechizu were charged with recovering one of Sukuna's fingers and came dangerously close to killing the students sent after it. His strength outstripped his younger sibling's, yet both fell well short of their eldest brother Choso.

His core power is the Rot Technique, which makes his blood corrosive enough to poison and break down anything it touches while letting him shape and steer that blood at will. Pushed to its peak as Maximum: Wing King, the blood pouring from his back forms wasp-like wings that boost his movement and let him strike from a distance with streams of blood. Once that blood breaches a target through a wound or mucous membrane, Decay sets in, spreading rot in a floral pattern that is meant to reduce a victim to bare bone within roughly ten to fifteen minutes. Through the binding vow Revealing One's Hand, he can speed that lethal process by openly explaining how the technique operates. He also reinforces his body with cursed energy, though Yuji's Black Flash shattered an arm he had braced to absorb a blow.