How to activate the statue with the skulls in the monastery woods? (Divinity: Original Sin 2)

eR1s0n.
In General, it activates the leach, which can be freed from the basement of Mordus, but the same leech said something about the blood and magic of the source, so MB there is a way and personally to activate it. I doubt that's possible.

sheikan
bless the blood of the MB?