Is Raki some kind of a monster magnet? I mean, first Clare, now loli Priscilla?? He seems to be getting a lot of action despite being the weakest thing in claymore.

About the awakening, I think that there are signs, not only physically but in the way the youki is gradually getting uncontrollable and its way of release. This way, even if you dont know the actual base youki like Undine, you can easily tell when they are going over.