It Goes Like This

The ancestors were enraged to see that. They tried to control the flow of Spiritual Energy, preventing it from entering the formations so they wouldn't explode. Unfortunately for them, Rean had already accounted for this possibility. Before the plan even began, Rean had already asked Sister Orb to charge the Bloodline Trial Formations with as much energy as possible. 

*Boom! Boom! Boom...*

All the remaining Bloodline Trial Control and Soul Stone Formations exploded at once. There was so much energy released that anyone nearby below the Saint Realm was wiped out almost instantly. Saint Realm Zasfins didn't die straight away, but they definitely had a very bad time.