Color Identity: B, G, U

Prerequisites

  1.  
    Myr Battlesphere
    Myr Battlesphere
    in your graveyard.
  2.  
    Muldrotha, the Gravetide
    Muldrotha
    and
    Time Sieve
    Time Sieve
    on the battlefield.
  3. You have not cast an artifact and/or a creature spell using
    Muldrotha, the Gravetide
    Muldrotha
    this turn.
  4. ({7} magic symbol)   each turn available.

Steps

  1. Cast
    Myr Battlesphere
    Myr Battlesphere
    from your graveyard by paying ({7} magic symbol)  .
  2. Myr Battlesphere
    Myr Battlesphere
    enters the battlefield, creating four 1/1 Myr creature tokens.
  3. Activate
    Time Sieve
    Time Sieve
    by tapping it, sacrificing
    Myr Battlesphere
    Myr Battlesphere
    and sacrificing the four Myr tokens, causing you to take an extra turn after this one.
  4. Repeat each turn.

Results

  1. Infinite turns.

Metadata

  1. In 42 decks according to EDHREC.
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