The True Bloods are very secretive about what their specific purpose is. They do, however, excel at many things, they will scout, they Dance well, but many, particularly the newer members seem to have a need to prove themselves to the other warrior societies, as good warriors. This is assumed to be due to the obscurity of the specific purpose the True Bloods serve to the Clan Chiefs.
Heirn, the sept chief of the Jindo, was accompanied to Alcair Dal by his society, the Tain Shari. All of the societies, including the Tain Shari, accompanied Rand al'Thor from the Sun Palace in Cairhien to Caemlyn in Andor to battle Rahvin and his forces. Tain Shari and Far Dareis Mai were called upon to scout around Rand's headquarters in Arad Doman.