Since I'm about to submit my ninja in the nearish future, and I like both the fluff and mechanics of this trait, I'm going to throw in a proposal to add Carefully Hidden, a human racial feat, to the approved list:
Ru grew up as a lower-caste child in Rhat'matanis, and his training is as a spy, so the idea of avoiding detection / exposure seems to fit him quite well. +1 trait to a single save seems pretty balanced to me, with the divination bonus probably not likely to be used very often, but nice on those occasions when it might be.
Your life as a member of an unpopular ethnic group has given you an uncanny knack for avoiding detection.
Benefit: You gain a +1 trait bonus to Will saves and a +2 trait bonus to saving throws versus divination effects.
Ru grew up as a lower-caste child in Rhat'matanis, and his training is as a spy, so the idea of avoiding detection / exposure seems to fit him quite well. +1 trait to a single save seems pretty balanced to me, with the divination bonus probably not likely to be used very often, but nice on those occasions when it might be.