The Void is a realization of nothingness and the cruel abyss.
No one understands anything about the Void, with the exception of their ultimate goal: the complete destruction of all worlds. The powerful members of the Void are essentially immortal and wield an unfathomable strength.
The only reason Setera is able to stand up and fight back against them is because Setera itself also rejects the existence of the Void, limiting their powers. However, the Void is growing in numbers and strength. You are the world’s final hope.