Oh there's so much to respond to that Rex has to pick and choose how to respond.

"I'm a person, too. And I decided to use my powers to help protect people, too. Don't have a Death Note on my Earth but that's a cool name, and Tristesse is even cooler." That's French, he's pretty sure. "I've got my Big Fat Sword that I can build outta my arm, but probably shouldn't whip it out here right now."