Oathblood Pact

Carve a plus sign into your hands and shake on an agreement. if that pact is broken then the person who broke said agreement can be tracked by the other member. the plus sign hurts in the direction of the promise breaker. This works like a compass to allow them to hunt each other down.

Some cultures use this for marriage and their vows, once a vow is broken, the spouse can hunt their oathbreaking spouse down and kill them, freeing them of the vow.

This is particularily done in the Yergraffe culture of the north