Near-infinite damageInfinite self-millNear-infinite landfall triggersPut all lands from your library onto the battlefield
How it works
Activate Avenging Druid by tapping it, dealing 1 damage to an opponent.
Avenging Druid triggers, causing you to reveal a land card from your library and put it onto the battlefield, and put all other cards revealed this way into your graveyard.
When the land enters the battlefield, Retreat to Coralhelm triggers, untapping Avenging Druid.
Repeat until no lands remain in your library and/or your library is empty.
This clever loop turns a simple tap into a cascade of land-drops and graveyard-filling by stacking a trio of unlikely allies. You begin by enchanting Avenging Druid with Fire Whip, granting it the active firepower needed to ping an opponent directly. That damage triggers the Druid's self-revealing ability, digging through your library until it hits a land and drops it onto the battlefield. The arrival of that new land immediately awakens Retreat to Coralhelm, whose landfall trigger untaps Avenging Druid so you can repeat the process all over again until your library is completely emptied.