So, anything to do with Eivanna's backstory here? Or Hawken's come to think of it, since he was the one who showed Eivanna how to use the powers of the Red Moon. Or heck, maybe even Vandheer, since he knew how to as well?
In retrospect, and nearly a year later, Vandheer Lorde figured out how to use the power of the Red Moon during the events of that game, not earlier, so probably not him. But it might have something to do with Eivana's and Hawken's backstory, since they were both trained by some kind of mentor.