I don't remember if I typed that or if I didn't end up posting it, but I thought Inhuman was a possibility, and it is funny that you brought up Crystal, because that's who I was thinking about last night.
Glad I'm not the only one who's crazy. The Inhumans thing looks like a possibility and I did read somewhere that it may be Marvels plan to replace the X-Men via the Inhumans in their cinematic universe. Who knows, I just enjoy the speculation.
Why would they 'wipe out' an entire village to get her back? Think of a more savage species/race. Deviants? Skrulls? Kree?
That's the question, but Raina's comments about "something internal" and "reaching natural potential" are at least suggestive to something like the Terrigen Mists. She was applying that to herself, as well as Skye. Combine that with a blue alien, a list from Sif that included the Kree, and the Kree's connection to the Inhumans, and that's where it led me. . .
I could be WAY off. Ha ha!