Things with Soren and Shiva have become . . . interesting, to say the very least, and I'm especially surprised that Soren has flung his fate into her hands. It's especially tough because Shiva has her own inner conflict on this war, and wants to believe the very same as Soren. There's also Mariel, who will probably be beside herself that her ally has switched sides.
Things are going to become very intense on this side of things, that's for sure. I wonder where this will leave Ren and Soren?
Mariel won't be too torn up about Soren's change in her current state. She will, at best, consider him a fool who lost his nerve in battle, something she doesn't have much patience for. At worst, he confirms what she expects from all demonic races, which is treachery and betrayal. And this was after Soren's actions was having her prepare a grudging thanks and a promise to give more of his kind a more fair chance in future.
Facing Shiva at all brought a crushing reality upon Soren; That he simply could not betray or kill her, even for a species he has such faith in.
Ren was the one thing that pushed Soren to Mystras's side in the end. Without him, he probably would've gone back to Kilkis, or just drifted as a wanderer. He treated him well as a prisoner and recently, he gave him something to do, I dare say live for. But, in the face of everything, Soren's loyalty to Shiva trumps all, despite their disagreements, he was always a very loyal Sentinel. He now knows for certain where he stands and even if it won't further his dream of the Overworld and World Below United, it's better than the alternative.
I do feel a little bad for Mariel. Sudden Back-up is now a Heel-Face Turner, who knew?