Complex sentence: Superman tries to get Mxyzptlk to say his name backwards at different attempts (one of them in his Clark Kent guise) and finally manages to trick Mxyzptlk into saying his name backwards by messing up the pronunciation of his name.
Split into simpler sentences: Superman tries to get Mxyzptlk to say his name backwards at different attempts (one of them in his Clark Kent guise). Superman manages to trick Mxyzptlk into saying his name backwards by messing up the pronunciation of his name.