Hantengu

Blood Demon Art: Duplication

Hantengu's Blood Demon Art splits him into autonomous emotion-clones that must all be destroyed at once to kill him, since any surviving fragment can regrow the whole. When cornered at Swordsmith Village, his clones merge into Zohakuten, his awakened form, before Genya and Tanjiro finally end him.

Hantengu's core form is a small, wrinkled old man, but his Blood Demon Art lets him split into multiple humanoid clones, each embodying a single emotion, ranging from a towering, muscular rage-clone to a tiny, cowering sorrow-clone. His final unified form, Zohakuten, is a hulking, four-armed giant.

The core Hantengu is a sniveling coward who blames everyone else for his own failures and hides behind his emotion-clones rather than fight directly. Each clone carries an exaggerated single trait, boundless rage, endless sorrow, or gleeful joy, reflecting fragments of his own repressed psyche.