Although I doubt they’ll add it, a clear effects power would be cool. It would, as the name suggests, clear the effects you have. It wouldn’t affect the gameplay too much as it would still take the points, but against stuff like speedy and reverse would be a bit OP.
Another power might be a constant tilting fever. It would make you tilt in the last direction that you traveled in. Like if you hit right, you would tilt right until you hit left or the effect wears off. This would be canceled out by angle turns though.*
A clear shot power could potentially be good. It would destroy any lines within a certain radius upon impact. It shouldn’t steal too much, however. I think that this is the one the devs would least want to be added to the game because it is too much like a mine/bomb.
(Edited) Dark fevers also might be cool. What it would do is it would darken your surroundings, so you can only see a small radius around you, while the rest of it would be black. It could also reveal the locations of other players, but those lights might be smaller.
Please tell me your ideas!
*Angle turns could slowly change the angle at which the curve is going at, but still rotate at 90-degree angles.