Devastating Onslaught + Mana Geyser + Eternal Witness

Devastating Onslaught

Mana Geyser

Eternal Witness

How it works

1. Cast Mana Geyser by paying 3, adding for each tapped land your opponents control.
2. Cast Devastating Onslaught by paying 4, creating two token copies of Eternal Witness with haste.
3. When the Eternal Witness tokens enter, they trigger, returning Mana Geyser and Devastating Onslaught from your graveyard to your hand.
4. Repeat.

This loop turns your opponents' heavily tapped board into an explosive engine by casting Mana Geyser to generate a massive surplus of red mana. You then channel that mana into Devastating Onslaught, creating two hasty token copies of Eternal Witness. Because Eternal Witness triggers upon entering the battlefield, each copy plucks the sorceries you just cast straight out of your graveyard and back into your hand, ready to repeat the entire sequence while generating infinite mana, tokens, and triggers along the way.