Activate Goblin Bombardment by sacrificing Forsaken Miner, targeting an opponent.
When you commit that crime, Forsaken Miner triggers, causing you to pay 1 to return it from your graveyard to the battlefield.
When Forsaken Miner enters, Mana Echoes triggers, adding C for each Skeleton and/or Rogue you control.
Resolve the Goblin Bombardment ability.
Repeat.
This loop is a masterclass in recursive recycling, where Goblin Bombardment acts as the sacrificial outlet that triggers Forsaken Miner to commit a crime against an opponent, paying its resurrection cost using the mana generated by Mana Echoes when the Miner re-enters the battlefield. Because the Miner shares creature types that scale with its returns, Mana Echoes yields a surplus of colorless mana with each cycle. Finally, Chromatic Orrery steps in to filter that raw colorless energy into any color you need, turning an infinite loop of skeletal sacrifice into an unstoppable engine of damage and card access.