You decide that there's nothing that makes someone want to die more than being the recipient of terrible punning. "Hey Infernomancer! I'd hate to BRAIN on your parade, but I wouldn't wanna zomBIE ya, 'cause I'm about to kick your ass, no ifs, ands, or GUTS!"
Unfortunately, your punning has the complete opposite effect that you intended. Rather than weaken the Infernomancer, it causes him to develop heretofore unknown superpowers, which he uses to pop your head like a grape.
"Sorry to POP in uninvited, but I've got a BONE to pick with you," he retorts, gathering your bones to make a throne for himself.
YOU HAVE DIED