While I took animation at college, the game teacher only had one thing to say about designing a UI - look at other popular games and copy what you think is awesome about their user interfaces, because other players probably think the same thing.
If you make your UI so complicated and confusing, most players will not play your game, so think about simplicity in design.
The more simplistic the UI for combat the better, as most players only use 3-4 powers on a consistent basis anyways. Having 10 slots to choose from may be way too much for the player and lead to less fluid game play.
For the next couple of weeks, I’m slowing down production for Christmas and New Years. I’ll only put a video up on Tuesday and Friday for the next couple of weeks.