[Plasma Expansion: Purple Sun]
Plasma gushed out of Eris's body, condensing around her into a massive ball akin to a purple sun, releasing so much heat that the cave started melting.
[Void Expansion: Devouring Void]
Darkness gushed out of Arad's chest, clashing with the purple sun and engulfing it in the blink of an eye.
Unlike their previous clash, Arad had expected Eris's expansion and smiled. Her purple sun hadn't grown bigger since the last time he saw it, probably due to her being unable to keep it stable more than a lack of power. And so to prevent it from exploding and tearing his void, he started crushing it with gravity magic instead of trying to eat it.
Eris could feel the ground around her purple sun disappear as Arad consumed her into the void. That had made it harder for her to feed the sun matter to expand it, but it wasn't a problem. She already had it big enough.
[Burst]
1-Yes, that was a Dark Souls reference.
2- Yes, this is a draconic wedding, chromatic style.