When Tatterkite dies, its persist ability triggers, returning it from your graveyard to the battlefield without a -1/-1 counter on it due to its static effect.
Resolve the Shilgengar ability.
Repeat.
This clever loop relies on Shilgengar, Sire of Famine to repeatedly sacrifice Tatterkite for value, transforming your graveyard into an engine that generates infinite Blood tokens and death triggers. The magic that keeps this cycle unbroken is Tatterkite's built-in static ability, which prevents counters from being put on it and completely bypasses the -1/-1 counter restriction normally imposed by the persist ability granted by Isilu, Carrier of Twilight (the back face of Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight). Because Tatterkite keeps returning with a clean slate, you can endlessly feed it to Shilgengar's sacrifice ability to fuel massive artifact synergies and mass graveyard returns.