there would be some intresting phylosophicle conversations

My money is on Lex to kill him after half an hour.

They would form an alliance, break out of Arkham, and try to kill Superman and Batman only to be defeated and sent away again.

Lex will try to kill the Joker.

Then will fail and The Joker will make Lex lost his mind, then Lex will try to buy Arkham and then they will end in a cell with Deathstroke.

Who isnt going to kill them, becuase lets face it, Deathstroke haves a reason to not kills them, then for some reason will end in the Marvel universe.

Nah, to be honest my money goes into the Joker makes so many jokes about the fact Lex lack of hair, to the point Lex kills himself.

The same Lex Luthor has always handled the Joker.

To Lex, human beings are lemmings, tools to be manipulated and used for his benefit. The Joker (see JLA: Rock of Ages) has been used by Lex before for his personal benefit. Most likely, he'd create a conflict with the Joker and use the ensuing chaos with the guards to escape.

Lex would go crazy from the Joker's rantings, then they go on a crazy murder spree and become soul mates then Harley will get jealous of Luthor, kill him. Joker kills her in a rage, then realises no one loves him anymore.

Joker bites Luthor's eyes out and bashes his head into a foamy red paste within two hours. He's physically superior and, as far as I've seen, never gets manipulated by Luthor unless he wants to be. He also has a home advantage. He might annoy/enrage Luthor a bit with madness before he finally snaps and murders him, giggling.

lux luthor's face after he realizes he shares the same cell with the joker

@moywar700 said:

lux luthor's face after he realizes he shares the same cell with the joker

LoL

Lex would use Joker to escape... Joker would use Lex for laughs.

This basic premise was explored in an (awesome) issue of Paul Cornell's Action Comics run, starring Lex Luthor... currently available in Superman: The Black Ring Vol. 2, by the way! :-P

I would actually love to see this relationship explored more extensively, with a reverse on the Superman/Batman comic offered pre-new 52, a Luthor/Joker book... filled with brilliance and chaos. I'd love that.

@sinestro_GL said:

My money is on Lex to kill him after half an hour.

This.

Lex would go crazy from the Joker's rantings, then they go on a crazy murder spree and become soul mates then Harley will get jealous of Luthor, kill him. Joker kills her in a rage, then realises no one loves him anymore.

@sinestro_GL said:

My money is on Lex to kill him after half an hour.

I agree, I don't think Lex would be able to handle the Joker in the same Cell as him