I'm having the same issue with Kana at my keep. I add him back to the party. I zone, and he leaves the party and appears to be permanently gone. Very odd.
Hmm.
Now I do have Nest Above the Clouds, and whenever I go back in to Teir Evron, I get the 2 +150 XP messages and the sighting of the small rain critter.
I"m having the same issue with not being able to do anything in Teir Evron, but I do not have The Nest Above the Clouds quest. I've never been able to pray to any god in here - just got in for the first time.
Have only a few of us had this issue?