I think Wizard already had this battle or at least a "deadliest villains list" that explained who was number one and how they'd kill the other guys on the list.
I think it was:
10: Bullseye
9. Sabertooth
8. Carnage
7. Joker
6. Doomsday
5
4.
3. Magneto
2. Lex Luthor
1. Dr. doom
Can't remember the other guys. Anyway, Carnage would just fall for any of Joker's tricks. And New 52 Joker is on another level.