The following description applies to MOD 16 - Undermountain.
Enhancement Power: Chance on hit to increase you and your companion's critical severity by up to 3% for 15 seconds when your companion is near. The value of the debuff depends on the quality of your summoned pet.
Player Bonus Power: 5% chance on At-Will use to increase your combat advantage by 1,000 for 10 seconds when attacking targets with less than 50% health. Each additional equipped Archon player bonus increases this bonus up to 1,000.