[@GreatSalmon]: Aah, sorry for being MIA. I've had a giant (figurative) gun to my head to work on stuff the past few days, but I'm here now.
Let's see...

Hm. Doopliss, huh? I think the biggest problem I have with adding him to the cast is that he feels more like a pseudo-joke character than anything else. That, coupled with the general power level trends of the RP (and the higher likelihood for him to be off in his own world instead of interacting with the cast) means that he'll likely not fit in. Especially considering the tone of everything right now. Paper Mario's pretty lighthearted until you start poking at the major antagonists, and honestly Doopliss isn't an exception.

So... Refusal, but not based on powers. Sorry, mate.