Bloodhunter's Flank

Heroic Tier
Prerequisite: Tiefling
Benefit: When you flank a bloodied foe, you and allies you flank with gain a +2 bonus to damage rolls against that foe. The bonus increases to +3 at 11th level and +4 at 21st level.

Published in Player's Handbook Races: Tiefling, page(s) 25.