• Arkham Asylum: Okay, so the main villain is Joker. Cool! That'll draw in a bunch of noncommittal fans, plus it's the first Real Batman Game of this kind!
• Arkham City: okay....its Joker again...but he's sick this time. He might even die! He definitely won't be in villain shape for the next game. Besides, there's a ton of other villains in this! It's not that focused on him!
• Arkham Origins: this is the PAST it's before he existed there's NO WAY Joker is behind this. Killer Croc, Black Mask...all perfectly good, non-Joker related peopl-GODDAMMIT ITS HIM
• Arkham Knight: he's DEAD. he's DEAD we have to be free there's NOOOO WAY he could be behind this one!!! He's definitely 100%.....oh look there he is