Activate Shilgengar by sacrificing Wingrattle Scarecrow.
When Wingrattle Scarecrow dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to Vizier of Remedies.
Resolve the Shilgengar ability
Repeat.
This clever loop is held together by Vizier of Remedies, whose replacement effect ensures that when Wingrattle Scarecrow uses its persist ability to return from the graveyard, the -1/-1 counter that would normally be placed on it is entirely prevented. This allows Wingrattle Scarecrow to be repeatedly sacrificed to Shilgengar, Sire of Famine over and over again without ever wearing down. Every single iteration of this cycle triggers Shilgengar to generate a Blood token, feeding an endless supply of sacrifices and artifact tokens to fuel your broader strategy.