Full disclosure: anything New Mutants or Alpha Flight will automatically get my interest. Dani (along with the likes of Cannonball, Magma, Karma (please bring the Vietnamese Asgardian weapons + Stark-level wealth and tech + empath/telepath into MCoC) and Rahne) was a favorite. So forgive my gushing about what may be a mediocre champ.
First: the Valk synergy is very nice, as shown below.

The following is also an interesting piece of utility. Tested on my Herc and it works like a charm. Still figuring it out on Nick because she wipes him out quickly. But this arguably makes her able to eliminate LMD, immortal as quick or quicker than anyone in game.

Finally, neuroshock that triggers at high sig on stun shrugs and (I think) purifies.

Finally, what seems like a fairly low stress and fun play style that blends a little bit of the typical mutant prowess features with some of the miss features of Spot or Ghost. Falter gives you a chance to quickly counter off a block. Her mechanics are clean and fluid and she flows from one attack to another (even in this laggy update—sorry, video won’t upload so here’s the Falter mechanic).

Is she Herc? There is no Herc but Herc. But she seems at first blush to be useful, fun and a solid damage dealer. I’ve had her less than 12 hours, and perhaps I’m overcome by nostalgia for the old New Mutants, but I’m tickled with how she translated into the game. Any additional thoughts welcome…
Dr. Zola