Complex sentence: After accidentally killing Pantha with a decapitating punch, Superboy-Prime is left shocked and horrified while the heroes try to contain Superboy-Prime, who kills or wounds several of them.
Split into simpler sentences: After accidentally killing Pantha with a decapitating punch, Superboy-Prime is shocked and horrified. The heroes try to contain Superboy-Prime, who kills or wounds several of them.