I haven't really talked about Dark Sun or how he plays into my redeemed Nexus/Nyx AU yet.
Nyx was the first one who met Dark Sun back when they were still New Moon. And Dark Sun kept showing up, despite saying he just wants to be left alone. Which in hindsight was a massive lie, I think he was watching them and picked them to be his victim. Its also possible that he knew what Ruin was doing and was waiting for it all to happen so he could enact his own plan.
Dark Sun is still the one who comes for them when in space and gives them a place to stay. They come to Nyx when they're at their most vulnerable, feeling emotional and discarded and also still actively in psychosis.
He enables them to hurt themselves, knowing full well what DSP will do to them. He enables them in general, wanting to nudge Nyx towards what will make his plan play out. He needs Nyx to get worse, to be at their worst.
He also still removes the chip from Nyx's head, which is part of why they have a TBI. Nyx will be a necessary sacrifice, which is why he tolerates having them around despite how much he hates all Moons.
Meanwhile, Nyx has lost everything and their life has been totally flipped upside down. Every day feels difficult and they're angry and grieving and desperate for some kind of comfort or sympathy. They want someone to finally understand their perspective and empathize with them. Dark Sun is not their Sun and they know that, but after such an awful ordeal they can't help but take some kind of messed up comfort in him. Dark Sun doesn't care about them, but he will indulge them if it means he gets to keep them under his thumb. Dark Sun picked up Nyx when they were extremely vulnerable, and he did that on purpose. Dark Sun gave them shelter, a safe place to stay, access to whatever resources they needed. That must mean something, right? And its hard for Nyx to detach themselves when Dark Sun plays into their emotions, when he tells them exactly what they want to hear. He makes sure he plays all his cards right to keep Nyx close.
Nyx tells themselves they don't care about what happens to them. They don't care if the DSP kills them. They know he must have a reason for keeping them around, and they don't care what it is. They're gonna die anyways, so none of it even matters.
But they can't deny that part of them wants Dark Sun to care for them. They miss their family, or at least what things used to be like. They miss Solar, someone who always understood them. Dark Sun preys on Nyx's emotions and vulnerability to try and make them as loyal to him as possible. He needs to make sure his plan goes well. But still he holds them at arms length, repulsed by them being a Moon. He will never fully give them what they need and it makes Nyx want it even more. Nyx wants to be useful and worth keeping around.
After Solar rescues Nyx, Nyx feels so dumb and used. They knew that Dark Sun didn't care about them at all, and now their mind is clear It's much more apparent. He just wanted something out of them. It makes Nyx feel stupid and frustrated. Nyx was very sick and vulnerable, physically ill from DSP and going through a terrible mental health episode and Dark Sun found it the perfect opportunity to swoop in and get what he wanted.
At some point early on, Dark Sun appears to Solar and asks him to take Nyx and come stay with him. Its his last ditch attempt to try and make the plan with Nyx work. He proposes the angle that Nyx's family id=s toxic, playing into Solar's emotions and how upset he is with Nyx's family for how they handled things.
But Solar sees through him because of how Nyx spoke about him. He knows Dark Sun is fake, and he's to blame for a lot of the situation they're in right now. He could have intervened but didn't and when he did intervene it was to make sure Nyx would get worse, like preventing Eclipse from reviving Solar.
Quite frankly Solar wants to kill him, but he knows he probably wouldn't stand a chance. So he just tells him to shove it up his ass and get lost, because if he shows up again he'll be prepared and WILL kill him.
