At the beginning of your combat phase, Mishra triggers, creating a token copy of the Machine God's Effigy (which is a copy of Dutiful Replicator), except it is a 4/4 Construct artifact creature with haste named Mishra's Warform.
When Mishra's Warform enters the battlefield, its Dutiful Replicator ability triggers.
Holding priority, activate Mishra's Warform using the Machine God's Effigy ability by tapping it, adding {U}.
Resolve the Mishra's Warform trigger from step 2, causing you to pay {1} to create a token copy of Mishra's Warform.
Repeat from step 2.

Infinite creature ETB

Infinite tapped creature tokens

Mishra, Eminent One

Dutiful Replicator

Machine God's Effigy

Cast Guardians of Koilos by paying {5}.
When Guardians of Koilos enters the battlefield, it and Replication Specialist trigger.
Resolve the Replication Specialist trigger, causing you to pay {1}{U} to create a token copy of Guardians of Koilos.
When the token Guardians of Koilos enters the battlefield, it triggers.
Resolve both Guardians of Koilos triggers, choosing to return nothing to your hand from the battlefield.
Cast Dutiful Replicator by paying {3}.
When Dutiful Replicator enters the battlefield, it and Replication Specialist trigger.
Holding priority, activate a mana-producing artifact by tapping it, adding at least {U}.
Resolve the Replication Specialist trigger, causing you to pay {1}{U} to create a token copy of Dutiful Replicator.
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.
When the Guardians of Koilos token enters the battlefield, it triggers, choose to return nothing to your hand from the battlefield.
Activate Krark-Clan Ironworks by sacrificing the Dutiful Replicator token and the Guardians of Koilos token, adding {C}{C}{C}{C}.
When the tokens die, Dross Scorpion triggers twice.
Resolve the first trigger, untapping the mana-producing artifact.
Activate the artifact by tapping it, adding at least {U}.
Repeat steps 14 and 15 one additional time.
Resolve the nontoken Dutiful Replicator trigger from step 7, causing you to pay {1} to create a token copy of Guardians of Koilos.
When the Guardians of Koilos token enters the battlefield, it triggers, returning the nontoken Dutiful Replicator from the battlefield to your hand.
Activate Krark-Clan Ironworks by sacrificing the Guardians of Koilos token, adding {C}{C}.
When the token dies, Dross Scorpion triggers, untapping the mana-producing artifact.
Repeat from step 6.
Once you have infinite blue and/or colorless mana, you may forego sacrificing the creature tokens.

Infinite blue mana

Infinite colorless mana

Infinite creature tokens

Infinite death triggers

Infinite creature LTB

Infinite creature sacrifice triggers

Infinite storm count

Replication Specialist

Guardians of Koilos

Dross Scorpion

Krark-Clan Ironworks

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

Ashnod's Altar

At the beginning of your precombat main phase, There and Back Again triggers, putting a lore counter on it.
There and Back Again's third chapter ability triggers, creating a legendary 6/6 Smaug creature token and causing you to sacrifice There and Back Again.
Activate Dutiful Replicator by paying {1}{U}, blinking it.
When Dutiful Replicator enters the battlefield, it and Deadeye Navigator's soulbond ability trigger.
Resolve the Deadeye Navigator trigger, repairing it and Dutiful Replicator.
Resolve the Dutiful Replicator trigger, causing you to pay {1} to create a copy of the Smaug token.
Put one of the Smaug tokens into your graveyard due to the legend rule.
When the Smaug dies, it triggers, creating fourteen Treasure tokens.
Activate three Treasures by tapping and sacrificing them, adding {2}{U}.
Repeat from step 3.
Once you have infinite mana, you may instead target any other token you control using Dutiful Replicator's ability.

Infinite artifact ETB

Infinite artifact LTB

Infinite artifact sacrifice triggers

Infinite artifact tokens

Infinite blinking

Infinite colored mana

Infinite copies of most tokens you control

Infinite Treasure tokens

There and Back Again

Deadeye Navigator

At the beginning of your precombat main phase, There and Back Again triggers, putting a lore counter on it.
There and Back Again's third chapter ability triggers, creating a legendary 6/6 Smaug creature token and causing you to sacrifice There and Back Again.
Activate Emiel by paying {3}, blinking Dutiful Replicator.
When Dutiful Replicator enters the battlefield, it triggers, causing you to pay {1} to create a copy of the Smaug token.
Put one of the Smaug tokens into your graveyard due to the legend rule.
When the Smaug dies, it triggers, creating fourteen Treasure tokens.
Activate four Treasures by tapping and sacrificing them, adding {4}.
Repeat from step 3.
Once you have infinite mana, you may instead target any other token you control using Dutiful Replicator's ability.

Emiel the Blessed

Combos with "Dutiful Replicator"