So, your answer:
................................................................................................
Kinda-sorta.
Tarrin's divine form is permanently marked by what he did...there's no way he can undo what was done to him, and no way to remove the taints that are inside him.
At least not normally.
It's not going to have much of an impact on his mortal body, though. When Tarrin finally reaches his mortal body, what he's going to do is put a spark of life into it, then access the powers of the mortal using the mortal shell. Since it's his own body, he's really the only one that could pull this off. The god can't reach beyond the rules of the universe, but the mortal can.
What Tarrin is going to do is un-deify himself using his Mi'Shara ability, something that only a mortal Tarrin can do. He's going to change his soul back into a mortal's soul. Normally that's absolutely impossible.
But remember, the first rule of Druidic magic is nothing is impossible.
Before he can do this, though, Dolanna has to stop giving him the power that he has...that's what he needs Niami to do for him. Make her stop, so he can undo what he's done to himself. Because her faith makes him a god, she has to stop believing in him so he can make the change back into a mortal a complete one. Without that clean slate, what he intends to do will fail.
Once he's a mortal again, the taint that he carried as a god will be eradicated, purged in the change back to a mortal soul...but the fur on his right arm will still be white, as a permanent scar of what he did. And it will be, til the day he dies.
Everything else will be as if he were a mortal though...at least physically. He'll lose his divine powers, and he'll lose his wings. But he'll always remember.
It's against the rules? Fine, gimme a marker and the rule book. *scribbles* Now it's not!
