Time Sieve + Myr Battlesphere + Teleportation Circle + Mishra, Eminent One

Time Sieve

Myr Battlesphere

Teleportation Circle

Mishra, Eminent One

How it works

1. At the beginning of your combat phase, Mishra triggers, creating a 4/4 Mishra's Warform artifact creature token.
2. At the beginning of your end step, Mishra and Teleportation Circle triggers.
3. Resolve the Teleportation Circle trigger, blinking Myr Battlesphere.
4. When Myr Battlesphere enters the battlefield, its first ability triggers, creating four 1/1 Myr artifact creature tokens.
5. Activate Time Sieve by tapping it and sacrificing the Myrs and Mishra's Warform, causing you to take an extra turn after this one.
6. Resolve the Mishra trigger, failing to sacrifice the Mishra's Warform token due to it no longer being on the battlefield.
7. Repeat each turn.

This clever loop sets up an infinite engine centered around recursion and artifact sacrifice. During your combat phase, Mishra, Eminent One animates a noncreature artifact into a temporary 4/4 Mishra's Warform token, while Teleportation Circle and Myr Battlesphere work in tandem at your end step to flood your board with four fresh 1/1 Myr artifact creature tokens. You can then tap Time Sieve and sacrifice those four newly made Myrs alongside Mishra's Warform to cash them all in for an extra turn. Because Mishra's Warform was already sacrificed to Time Sieve, the delayed trigger to sacrifice it at the end step safely fizzles, allowing you to repeat this process indefinitely.