The current gameplay mechanics allow you to check other players power relative to yours by checking their description. This is a good thing both for rp and game-play, as it can be explained by how strong you perceive them to be, and can be used to make fight-or-flight decisions. It would also make sense rp-wise though, that with enough skill you could alter others' perceptions of you. My suggestion is for a static skill that can slightly alter the readings other's would get. A good enough assassin would make sure they look harmless in order to assure they are more successful. Possibly there could be a skill for both directions, Deceit, for appearing to be weaker, and Bluff, for appearing stronger. A side-affect of the skills would be being able to see through others' changes, as a bluffer would know the tricks, and a deceiver know when others are pretending to be small.