Mark of Sentinel [Dragonmark]

Heroic Tier
Benefit: Whenever an enemy provokes an opportunity attack from you, you can shift 1 square as a free action before or after you make the opportunity attack.
You can master and perform the Eye of Alarm, Eye of Warning, and Magic Circle rituals as if you had the Ritual Caster feat.

Published in Eberron Player's Guide, page(s) 91.