Clayface. Especially if he is Bori Karlo who has all the abilities that the previous Clayfaces has:
Can appear in a malleable clay-like form and transform her physical appearance at will. Can temporarily duplicate the abilities of the being whose appearance he imitates.
Can cause another person to dissolve into a pool of protoplasm at his now deadly touch.
No longer has a normal skeleton, body organs, or even blood. Bullets can now pass through his body without harming him. Moreover he can now will his body to take on its original appearance or that of any other human being.
During his time in No Man's Land, Karlo's full power was seen. Apparently he now posseses the combined power of all the clayfaces, but also a fire producing power.
Fire + Carnage = beaten Carnage.