Blue Dragon Rage is a daily power available to the Barbarian class at level 25.[PH2:60]
Blue Dragon Rage
Barbarian Attack 25
Melee weapon
Target: one creature
Attack: Strength vs AC
Hit: 5[W] + Strength modifier damage, and the target takes ongoing 10 lightning damage (save ends)
Miss: half damage.
Effect: You enter the rage of the blue dragon. Until the rage ends, once per round when you hit a target with a melee attack, each enemy adjacent to the target takes 10 lightning damage.