!Interpretation of the climax

-->'''Superman''': I broke my oath. I killed him. Nobody has the right to kill. Not Mxyzptlk... not you... not Superman. ''Especially'' not Superman.

The climax of the story is Superman being forced to kill Mr. Mxyzptlk, and since he violated ThouShallNotKill he gives up his powers. This is either his noblest act... ''[[AlternateCharacterInterpretation or his most selfish.]]''

Mxyzptlk is far beyond Luthor, Braniac or even [[Film/ManOfSteel General Zod]] in that he's an EldritchAbomination, practically an EvilGod who was going to wreak havoc onto ''the whole universe'' if Superman had not stopped him, and the only way left was to put him down permanently. But Superman's inflexible BlackAndWhiteMorality means ThouShallNotKill is absolute, no excuses, not even for an God. Since he broke his vow never to kill, he feels he can't be Superman anymore.

But... how much good might Clark still have done for the universe if he didn't stop being Superman? [[ComesGreatResponsibility With great power comes great responsibility]], and it's just ''irresponsible'' of him to give up all his power and abandon the universe after such an extraordinary situation where he saved the universe.

By this, Creator/AlanMoore was saying how the simplistic morality of [[TheSilverAgeOfComicBooks the Silver Age]] is not enough for a more realistic world, a theme he would explore in ''ComicBook/{{Watchmen}}''.

(Also, by insisting that "''nobody'' has the right to kill", Superman is also being more demanding than the TropeNamer for ThouShallNotKill, because in [[Literature/BookOfExodus the original Hebrew,]] God's injunction is against ''murder'', and Superman's actions obviously fall under self-defense... )