An Heir of Blood being able to completely fuck someones life over without consequences. No matter what you tell your friends, your lovers, the Heir of Blood is always more believed. The Heir of Blood is the true friend and you're just the jealous lowlife. After all, what would the Heir do to hurt you? They've never hurt us, so...

I could see this more of a Witch thing, but the Heir could be liable to such a thing.