[quote=BlessedWrath]
I'm interested in this. I'd like to see more information about the limitations on abilities, as well as some examples of what would be allowable. I have a number of concepts I've been wanting to try out.
[/quote]

Well, powers shouldn't get too ridiculous. Explosions should be limited to a five meter radius at class 10. Keep them below what you would expect a low level god to have.
If you can come up with a good enough explainer, pretty much anything is allowable. I'd stay away from inherently OP powers like those that copy other's powers. More powerful abilities tend to use more energy, so try to balance it.