Activate Goblin Bombardment by sacrificing Melira's Keepers
When Melira's Keepers 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 loop relies on Melira's Keepers acting as an unyielding sacrifice engine, since its static ability prevents it from ever receiving the -1/-1 counters that would normally stop its persist recursion. By continually feeding it to Goblin Bombardment, you turn its endless death and rebirth into an infinite stream of damage. Meanwhile, Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight anchors your board with its back face granting persist to your other creatures while also giving your creature spells convoke, allowing your entire army to help cast threats as you dominate the game.