This crafty black-mana loop turns the self-sacrificing nature of Blood Vassal into a relentless engine by leveraging Enduring Renewal's replacement effect, which plucks the creature right out of your graveyard and bounces it straight back to your hand the moment it hits the dirt. Because you are constantly recasting the Vassal to keep the mana flowing, Bontu's Monument steps in to capitalize on those repetitive creature casts, passively draining your opponents' life totals while padding your own life pad with every iteration. It is a wonderfully self-contained cycle that fuels its own casting costs while grinding down the table to zero.