Kabukimono was created as a proof of concept to test the plans of the Archon Electro, the Raiden Shogun, for an indestructible puppet that could wield a Gnosis.
With his creation accomplished, the Shogun decided to leave him in a sleepy state, free of her control, as he had wept over his creation. After waking up, he came to believe that she had considered him a failure and dumped him.
He is a humanoid puppet with a characteristic that differentiates him from others, he has feelings, a heart.