Well imagine a world in which technology has advanced so far we can mess with time and space itself (although not evident sometimes it is used for various things). I mean this is in the FAR FAR future. A structure that has a radius as large as our solar system in which our story takes place. (yes a structure that large made by unknown methods. Perhaps stop and ponder how massive that is for a second.) Now this unfathomably large structure is widely empty, but occasionally floors contain humans, what used to "human", silicon creatures (basically cyborgs), artificially created organisms (aka grown in a test lab kind of stuff) and various robots. All civilizations are cut off from one another and know nothing about the rest of the world they live in. Through time and corruption, almost all information has been lost and various systems put in place LONG ago run amok. Machines called builders, build furiously expanding the structure even more every day. (Through the series this is one of the main antagonists as no one knows how to stop them anymore and if allowed to continue it is believed the structure may collapse, and anyone trying to get into a kind of network to access everything gets slaughtered by security systems.) This is the kind of world they live in. The main character killy has a ludicrously powerful gun that cuts holes in the structure that are miles long. He is an artificial being (that looks human) that was one of the original uh...well that would take a long time to explain but lets just say he was a pretty big thing way back when.
Anyways the point of all that was to explain to you the setting of this universe. It always inspired awe and wonder in me, and I think it has TONS of possibilities. Your choice however.
