Eberron - A New Era
You have a dragonmark.
Prerequisite: Member of appropriate dragonmarked race and house.
Benefit: You gain a least dragonmark and the use of one spell-like ability associated with the least dragonmark of your house. Five levels after you take this feat (so at level 6 if you take this feat at first), you gain a Lesser dragonmark. Another 6 levels later, you gain a Greater Dragonmark. So for a human taking the Sentinel dragonmark, he would gain the Least dragonmark of sentinel at 1st level, the Lesser dragonmark of sentinel at 6th level, and the Greater dragonmark of sentinel at 12th level. For non-humans and those taking this feat after first level, adjust the levels you acquire Lesser and Greater dragonmarks accordingly.
A saving throw against your dragonmark spell-like ability has a DC of 8 + your proficiency bonus + your Cha modifier.