Hm, well, I can't think of a specific ability, but this line in the flavor text was intriguing:
Some even come together and construct glistening structures to channel and focus the crystals of vast areas.
Maybe something involving making a second psicrystal of ice, further enhancing a psicrystal, being able to sopntaneously summon your psycrystal when in cold conditions... um... mainpulation of ice somehow to make it weaker or stronger...
Maybe something like Iceman's ability (Xmen), encase yourself in an ice body that gives you abilities. Oh, and cold immunity.