User blog comment:Smijes08/Arkham Knight: Joker- Ghost or Hallucination?/@comment-27124963-20151107175017

WARNING: LONG POST Joker wasn't "hijacking" anything. The Joker Infected were more or less... evolving, so to speak. And, like MDGeistMD02 said, Batman (and most likely the other Infected) was experiencing a combination of Lucid Dreaming and Out-of-Body Experience. Which is probably part of the transformation (or evolution, per se) of becoming the next Joker. And, like everyone else has been saying, Fear Toxin has the capability of making the whole process 20x's worse. It also makes the process go about 20x's faster. What took months for the other four took one night for Batman.

It also more than likely depended on how the state of mind and body was at the time of getting The Joker's blood. Christina just had a miscarriage, so of couse she's going to be depressed, which is why she was a perfect donor for being the next Joker. Johnny is egotistical and full of himself, so I suppose that may explain why he was also a good match... not sure why he needed the blood transfusion, though. Albert had to go do a routine check-up, in which I'm assuming that he was more than likely anemic, and knew that he was good at what he did for a living... he was a fighter. Henry, in all honesty, was just like Joker before he became... well... The Joker; kind-hearted, caring, loving, smart, had a family... then he had a hip replacement and needed a blood transfusion.

Batman's the odd-ball. He was aware of it happening. However, like the saying goes, opposites attract. But they're both as much similar as they are different, at the same time. Which, by default, makes him the perfect candidate of becoming the next Joker.

Now this may sound crazy but, if you think about it, each of the characters actually kind of resembles a piece of Joker's origin story (from The Killing Joke). Christina being Joker's wife, Johnny being the comedian, Albert being the Red Hood, Henry being the loving and caring husband trying to support his family, and Batman being the reason that Joker became the way he is.

I know, I know. Sounds bizarre. But I have a point. I also have the tendency to overthink things, but that's not the point. Now whether or not they did this on purpose, nobody knows. It could just be coincidental, for all we know.

And keep in mind that Joker more than likely had no idea such thing would happen. All he knew was the fact that he was dying. So... this was all probably kind of unintentional. Although he did tell say to Batman, "Now a little bit of me in you, too, Bats!" But he was referring to the blood, though it could be a foreshadowing thing. Or just... coincidental.