But now Lex Luthor doesn’t have Doomsday at his disposal anymore ... was able to remind the monstrosity of his past life as the Superman from the Inverse World and convinced him not to keep ...
injecting his body with a serum made out of Superman’s blood (which also created Doomsday) so that his heart could be transplanted to replace the one Clark lost to Doomsday. It is Kryptonian ...