The Varelsi are pulling stars into the void, for some purpose that will help them survive or escape an even greater force that is pursuing them. Throughout the entire game, Rendain is constantly telling us that he’s trying to save something rather than nothing, and that we’re just going to end up ruining everything. Honestly, Rendain is the good guy here. He’s using a necessary evil to save what little can be saved.
I’m sort of thinking that whatever is frightening the Varelsi also exists in the void, but the power of the stolen stars can keep it imprisoned/weakened and stop it from wiping out the Varelsi and also stop it from leaving the void to destroy the material reality.
Also, science note, removing a star by means of dimensional warp wouldn’t create a black hole at all. It’d just leave empty space, which would mean the planets would no longer have a gravity well to orbit and would all fly apart (hence the chaos of the dark universe)
