Actually 2 of them: Evanesce and Alter Time.
They are both under used and they both fulfill their role in a poor manner. This is my suggestion to solve them easily, invert them.
Keep only the positioning part of Alter Time and move it to tier 1. It would be a usefull way to move around during an encounter.
Any time you need to move out of some area and reposition you could make use of Alter Time. Because you're moving anyway, you avoid most of the damage so the healing component of Alter Time is unnecessary. Also as you don't need to balance 2 effects in one, you can lower the cooldown to be as good as the other 2 options on that tier.
Move Evanesce to tier 2, the talent already makes more sense as a defensive talent today. It will never compete with ice floes for movement, and the only time you would take it is to cheese some damage mechanics. If you put it on tier 2, you may actually see some use for Evanesce in comparison to Ice Barrier or Flameglow.
That's all.