Dash-then-Guard said:

My Lydia dissappeared from the face of Tamriel, and now I can't do any quest that requires a companion to follow me (Vilkas' purity quest, etc).

My Dareekus is really confused about where he lives. I enlisted him to the blades (as it was impossible to kill him) and he started spending all his time running to the blades HQ, then immediately back to his tent in darkwater pass, then back again as soon as he arrived.

Every few days or so i'd bump into him running in one direction or the other.