Pixie Haven [DF]

[Sense of Duty (Kittens)]

I have been trying to construct a pixie scholar, a character type seen frequently in video games. These games have an important albiet unusual trope that I don't know how to price. They can always find a safe place to go whenever combat starts, and the monstrers always ignore them. This is reminiscent of the Brotherhood Perk, but that does not incorporate the fact that the fairies do nothing during battle. How much should this advantage cost, if anything.