Zero.

The experiment known as Zero was a bio weapon genetically built for the u.s. military, built to take down any enemy that stood a threat to itself, it genetically was made a s a human to fit its powers into a genetic body built for its sheer strength, its strength is admirable and destructive, there power is insane above anything, there super human powers give it strength and speed a new level of adaptability ...however this experiment grew a mind of its own and brgan to have a conscious bent on someone..something, (this whole story takes place in the world of jujutsu kaisen)