Ashnod's Altar + Dross Scorpion + Dutiful Replicator + and 2 others

Mana needed: {11}{U}

U identity

Commander legal

The 5 combo pieces

What must be in place

You control a mana-producing artifact that can tap to produce at least {U}.

How to execute it

  1. Cast Guardians of Koilos by paying {5}.
  2. When Guardians of Koilos enters the battlefield, it and Replication Specialist trigger.
  3. Resolve the Replication Specialist trigger, causing you to pay {1}{U} to create a token copy of Guardians of Koilos.
  4. When the token Guardians of Koilos enters the battlefield, it triggers.
  5. Resolve both Guardians of Koilos triggers, choosing to return nothing to your hand from the battlefield.
  6. Cast Dutiful Replicator by paying {3}.
  7. When Dutiful Replicator enters the battlefield, it and Replication Specialist trigger.
  8. Holding priority, activate a mana-producing artifact by tapping it, adding at least {U}.
  9. Resolve the Replication Specialist trigger, causing you to pay {1}{U} to create a token copy of Dutiful Replicator.
  10. When the token Dutiful Replicator enters the battlefield, it triggers, causing you to pay {1} to create a token copy of the Guardians of Koilos token.
  11. When the Guardians of Koilos token enters the battlefield, it triggers, choose to return nothing to your hand from the battlefield.
  12. Activate Ashnod's Altar by sacrificing the Dutiful Replicator token and the Guardians of Koilos token, adding {C}{C}{C}{C}.
  13. When the tokens die, Dross Scorpion triggers twice.
  14. Resolve the first trigger, untapping the mana-producing artifact.
  15. Activate the artifact by tapping it, adding at least {U}.
  16. Repeat steps 14 and 15 one additional time.
  17. Resolve the nontoken Dutiful Replicator trigger from step 7, causing you to pay {1} to create a token copy of Guardians of Koilos.
  18. When the Guardians of Koilos token enters the battlefield, it triggers, returning the nontoken Dutiful Replicator from the battlefield to your hand.
  19. Activate Ashnod's Altar by sacrificing the Guardians of Koilos token, adding {C}{C}.
  20. When the token dies, Dross Scorpion triggers, untapping the mana-producing artifact.
  21. Repeat from step 6.
  22. Once you have infinite blue and/or colorless mana, you may forego sacrificing the creature tokens.

What the combo produces