Time Sieve + Myr Battlesphere + Emry, Lurker of the Loch

Time Sieve
Myr Battlesphere
Emry, Lurker of the Loch

Requires
Myr Battlesphere in your graveyard. All other permanents on the battlefield. Emry does not have summoning sickness. 7 available each turn.
Steps
  1. Activate Emry by tapping it, allowing you to cast Myr Battlesphere from your graveyard this turn
  2. Cast Myr Battlesphere from your graveyard by paying 7
  3. Myr Battlesphere enters the battlefield, creating four 1/1 Myr creature tokens
  4. Activate Time Sieve by tapping it, sacrificing Myr Battlesphere and sacrificing the four Myr tokens, causing you to take an extra turn after this one
  5. Repeat each turn
Results
Infinite turns.