Bloodline Curse in Storm Front??
So, it's stated here that the Bloodline Curse, as part of its 'attack' can blow a victim's heart from their chest, and that leads Harry to figure that it was being used in the first book by Victor Sells. Except... it would require using a relative of the victim to help target/fuel it; it's been awhile since I've read
Storm Front, but I don't remember a big deal being made about family members of the victims disappearing or dying during the events of the book.
- The bloodline curse requires a great deal of power to go off as intended, with Sells the power was weak enough that it only hit one person and the person he was with at the time (due to "two hearts as one" at the time. Or alternatively as some believe she was pregnant and they got killed due to proximity despite the weakness.
