Stormweaver Trilogy 2. Stormweaver

When your lover helps you escape by betraying you to the enemy.. Alissa finds a secret Resistance outpost in Pangaea's icy northern wastes, while trying to understand why Reith seems to have abandoned her--as well as trying to remind herself that this is so not the time to fall for Janis, the charismatic rebel leader. As she faces a giant snow tiger she suddenly discovers that she can no longer rely on her enhanced abilities for survival in this uncertain new world.
But the desert holds new dangers and the oasis cities are unprepared. Stolen military secrets, disrupted route-finding, and ambitious warlords are converging to inflict a deadly conclusion. The Resistance will be forced into open warfare before they have enough preparation to take on the heavily-armed invaders. And sometimes victory demands too high a price. The aftermath of a deadly battle in the desert sparks a power struggle at the heart of Irithen's military leadership.
It will take everything Alissa and Reith can do to avert a disaster that would lead to their ultimate defeat. And that is when Alissa has to decide when breaking the rules to win has gone too far. Books 4, 5 & 6 of the Stormweaver series, the far-future fantasy epic from Jay Aspen.