Progenitor Mimic + Time Stretch + Shipwreck Dowser

Progenitor Mimic

Time Stretch

Shipwreck Dowser

How it works

1. Cast Time Stretch by paying 8, taking two extra turns after this one.
2. At the beginning of your next upkeep, Progenitor Mimic triggers, creating a token copy of Shipwreck Dowser.
3. When the token Shipwreck Dowser enters the battlefield, it triggers itself, returning Time Stretch from your graveyard to your hand.
4. Repeat.

This brilliant loop relies on a continuous engine of recursion and extra time. Once you cast Time Stretch to claim your consecutive turns, the non-token Progenitor Mimic steps in during your upkeep to continually manufacture fresh copies of Shipwreck Dowser. Each time a token Shipwreck Dowser arrives, its triggered ability plucks Time Stretch right back out of your graveyard and into your hand, ready to be cast again. Thanks to Shipwreck Dowser's prowess, you even pick up a growing combat threat along the way, ensuring that every upkeep yields both a stolen turn and another relentless copy.