How, exactly, is a FreeSpace civilization supposed to build a Death Star, never mind power it?
The same way that anyone else would build and power a death star, you fool. I am surprised that I have to explain these things.
Wait, wait, I've got a better idea. The GTVA builds a hundred
death stars! And they would be escorted by Disco Stars, which would have a hundred smaller projectors that could target fighters. The Death and Disco stars would in turn by protected by a Death Sun, which would envelop everything in a massive force field, creating a mobile solar system of angry, weaponized moons of DOOM. It would annihiliate entire dimensions just by entering subspace.