Among Batman's many defining attributes, one quality that occasionally alters depending on who's writing the character is his philosophy regarding taking a human life. Whether it's the more modern, comic-based tradition of characterizing Batman with a strict "no kill" rule - or an interpretation like Zack Snyder's Batman v Superman: Dawn of Justice that shows Batman as passive in regards to killing - fans continue to debate which ideology fits the Dark knight best. But if there's one thing bat-fans are unanimous on, it's that, without question, there would be no version of Batman without the deaths of Martha and Thomas Wayne. And at one point, Bruce nearly broke his "no kill" rule in a truly extreme manner, by almost taking his own life with the same gun that killed his parents.
One of the great conflicts for Batman is the struggle with his own sanity. Some of his most notable stories have questioned the rational of a man who dresses like a bat and spends his nights beating on criminals. Is Batman simply a twisted excuse for a traumatized man to deal with his damaged psyche, or does Batman actually bring about the hope and change he sets out to inspire? One famous bat-story brought that question to the forefront, and nearly broke Bruce Wayne in the process.
In Batman: Ego, written and illustrated by Darwyn Cooke, Bruce spends the bulk of this self-contained narrative arguing with the personification of his own fear. This dual identity manifests within Bruce's psyche, assuming the form of a surreal bat-monster after a badly injured Batman returns to his cave. Having just witnessed one of the Joker's henchmen committing suicide (immediately after confessing to killing his own family, nonetheless) as a direct result of Batman using him as a pawn in his strategy to take down the Joker, Bruce's fragile sanity unleashes the hallucinatory monster as a kind of subconscious questioning of his own motives.
Bruce stands his ground as the demon puts him on trial, fighting with all his might not to succumb to the specter's insistence that Batman should be allowed to kill his enemies. Finally, the monster spawns the very gun that killed his parents into Bruce's hand and tells Bruce to kill him, insinuating that killing the manifestation of his fear will finally absolve him from his horrible burden of responsibility. Bruce points the gun at the monstrosity, dead set on being freed once and for all, but manages to stop himself just before pulling the trigger. Bruce disassembles the gun and tosses it away, acknowledging that pulling the trigger would be the same as committing suicide.
As it turns out, the monster was testing Bruce. By acknowledging that killing the monster would mean killing himself, Bruce manages to come to terms with the fact that his fear is a very part of his being that can't be escaped, only embraced and guided for the better. Bruce is forced to accept that there is a deep, dark insanity to his becoming The Batman, but as long as his rational mind guides that sanity and sets strict parameters, his pursuits will continue to be seen as a guiding light for others. Bruce managed to emerge from his battle with the abyss restored and more mentally strong than ever.