I'm sure the Sentinels RPG will have rules for creating a Nightmist-like character, and if they have the rules for it, they'll probably have a pregen built with them. I'm hoping that's true for The Scholar, too. Unless they were killed off because >G couldn't figure out a way to make their mechanics work in the RPG?
If Christopher can make Mr. Fixer work in Tactics (he's a BIG reason I hope Broken City gets made) he can make Nightmist or Scholar work in an RPG.
Nah, I honestly don't think that has anything to do with it.
If there's anything I've learned from playing and GMing in FATE (the Dresden RPG, specifically), it's that you can make just about anything work.
Yeah, RPGs are the easiest thing to play with power levels on. I seriously doubt the viability of Nightmist and The Scholar for the RPG was a concern.