Activate Yawgmoth's first ability by paying 1 life and sacrificing another creature.
When the creature dies, Vindictive Vampire triggers, causing you to gain 1 life and dealing 1 damage to each opponent.
Resolve the Yawgmoth ability, causing you to draw a card and allowing you to put a -1/-1 counter on up to one creature.
The Locust God triggers, creating a 1/1 Insect creature token with flying and haste.
Repeat.
This engine transforms your sacrifice outlet into a self-sustaining web of triggers by turning every card drawn into a fresh sacrifice fodder. As Yawgmoth, Thran Physician sacrifices a creature to draw a card, The Locust God immediately replaces that lost piece by spinning out a flying Insect token. Meanwhile, Vindictive Vampire quietly drains out your opponents and loops your life total back together with Yawgmoth's activation cost, creating an endless cycle of death, damage, and rebirth.