Blood pacts create a terrible and extremely difficult situation.
What is a blood pact?
A magical doorway.
A person has likely opened up doorways for a demon to cross over to our world.
Massacre of the Innocents
The execution of all male children two years old and under in the vicinity of Bethlehem. It was rumored to be myth or folklore. The massacre is "perhaps the most legendary".
A true reign of terror.
It was a Alcheon priest in the early 1400s, saw a sign in the scrolls predicting the birth of a powerful baby from the Santorians. In it was marked by the Santorians victory. In a rage he sent Azoreans. He ordered the slaughter of infant children to avoid it.
The Santorians, in their grief, retaliated.
This however went on for several decades before Azorean members and Santorian members secretly met to evoke the ancient rite of the Blood Pact.
Blood is typically seen as very powerful magic and producing energy.
The Blood Pact involved a rite whereby they let their blood flow into a cup; the blood was subsequently mixed with wine and drunk by the one casting the incantations.
Done right the blood ritual is used for protection.
Once made, the Blood Pact is supposedly impossible to destroy, it will last till the child grows to maturity and into their powers.. Only then can a child of both sides be harmed.