Zardnaar
Legend
With the idea that they could have found a path to redemption had Adar made different decisions. They had free will, and used it to make the wrong choice.
Given that the Eregion plotline is heading for a Sauron victory, I think they have to end on a note of hope, and the Stranger making the right choice and not becoming Saruman.
It occurred to me that Gandalf says "into the East I do not go". Not "I've never been East". Maybe he does some deal with the Dark Wizard to never return to the East?
I'm thinking they betray Adar and willingly pick Sauron.
And Sauron seems to be able to over ride free will. As I understand it they go extinct.