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 Viscera Seer ability.
Repeat.
This clever loop turns Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight into an endless sacrifice engine by granting Tatterkite persist while it's on its Isilu, Carrier of Twilight face. Because Tatterkite's static ability prevents counters from ever being placed on it, the persist trigger successfully returns it to the battlefield without the usual -1/-1 counter penalty. Viscera Seer provides the free sacrifice outlet needed to start the loop, letting you continuously churn through your deck with infinite scry triggers while generating an endless chain of deaths and sacrifices.