OR this may have been what actually happened and what Bruce has been living in is literally Hell. A world where a tragedy in your past has polarized your every action to the point of you not growing and eventually dying alone? Sounds like Hell to me. And to Bruce we all know who the Devil is.
Only now after two decades of Arkham Asylum being published are people collectively going, "Oh duh! This son of a bitch isn't human!" Everything from his inability to die, an insanity bordering alien logic, and his ultimate goal to let everyone's ID roam in violent freedom is a big indicator that The Joker has always been a god of evil.
Cool! Iconic and immediately recognizable, like all this series
You know, when I first saw one of these, I wondered something like "So who's the cranky kid who's trying to kick Batman fans in the teeth?" But by the time I saw the third 'un, I'd realized both how much skill AND how much love of Batman went into these. You do great work!