Hmm, I like the idea of them being able to use their abilities as weapons. I would reserve that type of ability to our (The RPers) characters only, since they are more powerful than normal. Possibly they could create small tremors, and blasts of sound. Possibly control sound around them and others, as if they were physical objects easily malleable. I'm keeping in mind our characters are MUCH more powerful than regular humans, while still being relatively weak when compared to these creatures. None of our characters can move in the fourth dimension... which is our enemies greatest power. So, pretty much anything we come up with isn't going to be too much of an advantage. I'll say sound will be better than sight at some points, being able to pinpoint where the creatures might end up, since they don't move like normal three dimensional beings. (TELEPORTATION ANYONE!?)