Like you, I've noticed there's a lack of Keeper RP. I'm not quite interested in making a new tribe, as Nako has other priorities right now (plus she's still quite attached to her mother's tribe), but I see no reason why her tribe couldn't have ties to others within the Shroud. Nako was raised in a nearly-feral tribe/family group within the Shroud, but branched out to become a Wailer for a while, causing some strain with her family by doing so. She's been in the Shroud and Gridania for most of her life.
