I am playing a somewhat nonthreatening alien in 6E, and wanted to buy a PREsence boost to reflect him "putting on his game face" (He unhinges his jaw, bares his two rows of shark-teeth, causes his eyes to glow red, makes lightning arc off of him, all while growling and drooling). I don't want to make it an Aid, that's too random; I don't wnat a Shapeshift, either, having to buy Sight, Touch, and Hearing separately makes it seem illusory when it isn't; I figured I would buy it as Characteristics, but it would have to be activated, and would possibly cost END.
My question is this: Is there a hard-&-fast list of Limitations that are applied to Characteristics bought as Powers, as well as their Values?