I wanted to create a hero who could freely control her position in space and time, an all that entails: flight, teleportation, time travel, super speed; all limited only by stamina. The way I explained this was by giving her the single ability to manipulate gravitons, a (as of yet only theoretical) particle that mediates gravity. By concentrating them in one place or sucking all of them out of it, she could distort spacetime and thereby "lens" it around her, creating dips and bulges to bounce herself around.

The trouble is this power seems a bit...broken. For example, I realized that this power, to be implemented in any way that makes sense, also includes some degree of telekinesis. If she can only grab gravitons right in her person, that's probably not enough to do anything. But if she can pull in or push out the ones further away, she should logically be able to put them around a point outside of herself too, teleport or time travel objects for instance.

I'm wondering if there's any logical way to cap this besides just stamina, or what a good power for actually combating it would be in a world without magic