* AlternativeCharacterInterpretation: Superman gives up his powers when he is forced to kill Mr. Mxyzptlk. This is either his noblest act... or his most selfish. See the [[Analysis/WhateverHappenedToTheManOfTomorrow Analysis page]] for why.
* AntiClimaxBoss: The story seems to be building towards a major confrontation between Superman and Brainiac, but Brainiac is ultimately defeated by Lana, whose MercyKill of Lex [[PuppeteerParasite robbed Brainiac of a viable host]]. Instead of a great battle, Brainiac simply breaks down at Supermanís feet. Superman's true greatest threat is [[spoiler:evil!Mxyzptlk]].
* CompleteMonster: ComicBook/{{Brainiac}}. He brainjacks Luthor in the most horrifying way possible, murders most of Superman's remaining friends, and is completely devoid of anything resembling a conscience.
* ContinuityLockout: Shades of this, since it references Superman's history, both famed and obscure. However, that's the entire point of the two-parter, to briefly touch on the Superman mythos. Do you ''really'' have to have read the Jimmy Olson book in which he became Elastic Lad to enjoy the story?
* EvilIsCool: Despite appearing in a few panels, Moore's revision of Mr. Mxyzptlk, has remained an iconic rendition of that character. Post-Crisis authors increasingly nerf him because Moore demonstrated quite successfully that the Fifth-Dimensional being is capable of being Superman's worst enemy.
* HarsherInHindsight: The Prankster and Toyman were re-imagined as psychopaths in the Post-Crisis universe, making their decision to get back at Superman by murdering Pete Ross and outing Superman's secret identity more disturbing in retrospect.
* HeartwarmingInHindsight: Superman and Lois being parents to a son named Jon in the final scene eventually happened in the main canon thanks to ''ComicBook/DCRebirth''.
* HilariousInHindsight:
** Jordan Elliot looks like [[Comicbook/{{Watchmen}} the Comedian.]]
** Even more hilarious, the [[https://pbs.twimg.com/media/Cl7HKSTXIAIaEuZ.jpg original printing]] had a "Who Watches The Watchman" blurb in the area reserved for the barcode. Considering the events of ''ComicBook/DCRebirth'' and the post-Crisis Superman...
* OneSceneWonder: Mr. Mxyzptlk appears in one-scene, and less than ten panels, but to say he steals the scene is an understatement.
* {{Narm}}:
** Batman and Robin attacking Brainiac's energy shield with sticks.
** After Brainiac attempts to continue the battle by taking control of Luthor's corpse, in one panel it looks like Luthor is making a derp face.
* TheyWastedAPerfectlyGoodCharacter: Lex Luthor, Superman's greatest ArchEnemy, the greatest criminal mind of our time, is reduced to a meat puppet in his final (Silver Age) appearance. THAT'S how Lex Luthor goes out. Moore does treat him respectfully by noting that Superman considers him and Brainiac his two greatest threats, but Brainiac is shown as EvilerThanThou and then [[spoiler:Evil!Mxy comes in and steals the show]].
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