The latest in a series of previews for Rift update 3.6 has been published on the game's official site. The Frostkeeper Ascended Soul is the subject of the latest post.
The Frostkeeper is a healer that makes use of water and earth elements. Frostkeepers can also provide shields / barriers to protect party members from damage. On the DPS side, Frostkeepers utilize powerful AoE abilities such as Frozen Ground. According to the Rift team, this Ascended Soul pairs well with Chloromancer and Warlock.
You can read a lore piece for Frostkeeper background on the Rift site.