Iron Man says, "Ya know, Loki, I really appreciate your view of world domination. I'mma gonna join your team."
Hulk says, "Me with aliens."
Batman says, "Bane! My man! Let's hook up! Together we can take over Gotham!"
Spider-man says, "Sure you're an evil, limb regenerating slimeball, Lizard, but I like your style! Let's spray a green mutagenic cloud over the city and make everybody lizards!"
Superman says, "Lex, you're a greedy, ego-centric, malicious megalomaniac, but you talked me into joining your team! I'll wear a big ol' purple and gold 'L' on my chest now!"
Doofenshmirtz says, "Perry the Platypus, I'm so glad you've come over to my side. You can still be close to the children."
Dr. Who says, " 'Exterminate! Exterminate!'"
... and steve nash joins the lakers...