Fushi is an immortal being that can take the form of anything that has given him stimuli.

His original form was a featureless white sphere. Without consciousness, he copied the first thing he bumped into, which happened to be a rock. Soon afterward, he became moss and stayed like that for some time. When a wounded wolf wandered close in the middle of winter and died, the immortal copied the wolf. He retains the ability to turn into these things.

Later, after the death of The Nameless Boy, he mimicked the boy's appearance and took the form of a young boy with white hair, pale complexion, and green eyes. He wears a short, brown fur cloak and a light blue shirt and pants with fur boots. A rope dangled from his hand and neck as The Nameless Boy died holding Joaan's leash, though the latter soon disappeared. The injury that took The Boy's life is also present on Fushi's left leg. Fushi commented that this form felt like it belonged to him the most.