Activate Goblin Bombardment by sacrificing Melira.
When Melira 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 Goblin Bombardment ability.
Repeat.
This elegant engine centers around Goblin Bombardment, which provides a free outlet to sacrifice Melira, Sylvok Outcast over and over again. While Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight's night face grants persist to keep dragging Melira back from the graveyard, Melira's own protective static ability steps in to cancel out the incoming -1/-1 counters. Because Melira prevents those counters from ever being placed, the persist trigger never sees a counter on her, allowing her to loop infinitely and rain down endless damage on any target.