You drown out the clash of combat and focus on one type of energy, which you channel into your spells for extra power.

Daily   ✦     Arcane
Minor Action      Personal

Effect: Choose acid, cold, fire, force, lightning, necrotic, poison, psychic, radiant, or thunder. Until the end of the encounter, whenever you use an arcane power that has the chosen keyword, you can roll the damage twice and use the higher result.

Published in Arcane Power, page(s) 34.