I just read maximum carniage a couple weeks ago and read the killing joke this weekend and this question poped into my mind. I really don't know. I think Carnage is more random where as the Joker does somethings that come across crazy and anarkic but there is a method to his madness. But they both are very freakin sadistic.
As much as this should be self-explanatory it is not. This is used for actual fights between 2 or more people. Just because it’s a “versus” does not make it a battle. They have to actually be fighting, otherwise it's an Off-Topic or General Discussions depending if it involves comics or not.
An example of a topic that does NOT belong in the battle forums is: the Simpsons vs Family Guy, which show is better? This is NOT a battle, it’s just asking which show is better.
Battle related threads, such as questions whether <inser character>'s powers should be included or asking who's the best battle debater should be directed to this thread. That way it doesn't clutter up the battle forums to show actual battles.