Rotation:
Buff up firstly using blue betty, ice fortress, then elemental drain on as many targets as you can, spiked bone shield x1.

Switch to front bar, degeneration x1, force pulse x2, elemental weapon and light attack combo x2 or screaming cliff racer x2, pulsar x1 or x2.

Switch to back bar if healing is needed or for rebuffing, make sure to keep spiked bone shield active as much as you can and continue to use elemental drain. Use ice comet if in a sticky situation or eye of the storm for extra damage. This rotation and skills can be very useful for group pvp and just with a few changes pve as well.