I think that’s what makes these characters interesting.
In the recent cinematic, while Fyrakk is interrogating the Green Dragon, there’s a scene where he says “Just let me in.” During this portion of the cinematic however, his voice alters and his eyes begin to glow purple.
I think this is more an indication of the Void wanting access to the Emerald Dream, and corrupting the seed, than Fyrakk wanting an increase in power.
His power surely increased with the absorption of the Shadowflame, but he’s never really shown the full potential of this. There really hasn’t been that “I crave more powa!!!” scene, so it feels more void seeking than anything else.
However, he is infused with the Shadowflame, there’s really no coming back from that, surely the Void wouldn’t want to let such a vessel go-- so unless there’s some divine intervention by Elune, the titans or some other cosmic being, he’s probably a goner.
Something interesting with his character though, is the fact that he was still capable of reasoning. He could end up having an internal conflict if the Void tries to take over his mind by force.
As for Iridikron, he may be working with the Void, but he’s shown to not make personal sacrifices. He’s not adsorbed any void infusion, infinite shenanigans, or any other cosmic force to my knowledge.
While I don’t think he will be redeemed, I do think he would be the least likely to die this expansion due to showing a level of respect to the strength of our PCs.
Vyranoth seems likely to turn on Fyrakk once she witnesses the extent of his destruction.
However, there is a possibility that she won’t turn “good,” and they will add a bit of a twist (to Blizzard’s standards) and she will go full vengeance if we just put down Fyrakk right away because story wise, we are still Titan backing god killers.