Winter Phoenix Rage is a daily power available to the Barbarian class at level 19.[PH2:58]
Winter Phoenix Rage
Barbarian Attack 19
Your blow erupts in grasping frost as the spirit of the winter phoenix enters you. As your rage, vitality surges through you to ward you from death
Melee weapon
Target: one creature
Attack: Strength vs AC
Hit: 3[W] + Strength modifier cold damage and the target takes ongoing 10 cold damage (save ends).
Miss: half damage.
Effect: You enter the rage of the winter phoenix. Until the rage ends, you gain regeneration 5 + your Constitution modifier. In addition, the first time you drop to 0 hit points or fewer, you can spend a healing surge as an immediate interrupt.