Activate Shilgengar by sacrificing Boonweaver Giant
When Boonweaver Giant dies, False Demise triggers, returning Boonweaver Giant from your graveyard to the battlefield
When Boonweaver Giant enters, it triggers, returning False Demise from your graveyard to the battlefield attached to Boonweaver Giant.
Resolve the Shilgengar ability from step 1.
Repeat.
This elegant loop turns a continuous cycle of sacrifice and rebirth into an infinite engine, powered entirely by a recurring trigger and a steady supply of blood. By using Shilgengar, Sire of Famine to sacrifice Boonweaver Giant, you trigger False Demise to immediately resurrect the Giant, which in turn uses its entrance ability to pull False Demise right back from the graveyard and reattach itself. Meanwhile, Shilgengar's ability conveniently rewards each sacrifice by churning out a Blood token, allowing you to easily generate infinite artifact and death triggers along the way.