Time Sieve + Myr Battlesphere + Teleportation Circle + Panharmonicon

Time Sieve

Myr Battlesphere

Teleportation Circle

Panharmonicon

How it works

1. At the beginning of your end step, Teleportation Circle triggers, blinking Myr Battlesphere.
2. When Myr Battlesphere enters the battlefield, its first ability triggers twice, creating eight 1/1 Myr artifact creature tokens.
3. Activate Time Sieve by tapping it and sacrificing five Myrs, causing you to take an extra turn after this one.
4. Repeat each turn.

This loop locks down the game by generating an endless succession of extra turns, fueled entirely by a repeating cycle of robotic reinforcements. At the heart of the engine is Myr Battlesphere, which enters the battlefield to deploy its miniature army; with Panharmonicon amplifying the entry trigger, it floods your board with eight Myr artifact creature tokens instead of the usual four. During your end step, Teleportation Circle resets this giant construct by blinking it for a fresh wave of tokens, giving you a steady surplus of artifacts. Finally, Time Sieve harvests five of those newly minted Myrs to buy you another full turn, ensuring your opponents never get to untap again.