* Devilman's first battle. Frightened and maddened out of his wits due to being a human in an underground chamber filled with menacing, nightmarish monsters, Akira dashes off. Right then Amon tries to possess him... and Akira manages to defeat him -one of the most powerful demons ever- in his mind and steal his power. Straight after he transforms into Devilman and starts brutally slaying the several dozens of demons filling the room.
** Not to mention this is when Akira shouts this iconic line:
--> '''I! AM! DEVILMAN!!'''
** Even before that, in the OVA, Akira shows some much-needed guts and 'pure of heart' when he stands up to three punks who killed a bunch of rabbits. He takes a lot of pain in just protecting the last rabbit and the gang boss backs off when he sees how tough he is.
* In the OVA "Amon: Apocalypse of Devilman", Akira loses his human heart due to a tragic loss and thus is fully taken over by Amon. In the climax, Amon attempts to destroy Akira in a battle within their conjoined soul. Akira proceeds to show just how badass a true Devilman is.
** Amon himself is given plenty of spotlight to show how much of a fearsome demon he is; as the demon equivalent to a War God, Amon doesn't care whether the people who face him are human or demon, he'll take them out all the same.
** Amon subduing a demon general by throwing ''a train'' straight through a building at him.
** Akira is mentally and spiritually ''broken'' when Amon comes a-knockin', and for most of the fight, Amon completely dominates the battle. And then, Devilman gets a HeroicSecondWind. He has nothing left to fight for, but he gets up, and he pounds Amon in the face. Once. Twice. [[RapidFireFisticuffs Repeatedly]]. Even though Devilman has lost everything else, he still overcomes Amon with the determination of his human spirit.
*** To hammer home exactly how much a Determinator that Akira is in this fight: Amon had punched clean through Devilman's torso immediately before the aforementioned RapidFireFisticuffs. Akira doesn't just shrug it off, he grabs the offending limb- which is ''still impaled in his chest''- [[YouWillNotEvadeMe to keep Amon in arm's reach]] for the near minute that Devilman spends using the demon's face as a speedbag.
** Finally faced with Satan himself, Akira stares him down as the environment intensifies, in prediction of the ultimate showdown, only to stoically walk right past him, rejecting his former ally and leaving him to his [[PyrrhicVictory "victory"]]. As for whether [[DownerEnding the rest of the story]] would stay the same after this... maybe that's up to you to decide.