C1629 Underground City

"Heh heh, the kind that can blow up a thirty meter hill and flatten it to the ground!"

"Also, boss, I have also researched a black technology, which even Heavenly Star City doesn't have. Devouring a black hole, after these four types of energy fuse together and control the point of eruption, a black hole will form, which is what you call awesome. If there's enough energy