Activate Cauldron of Souls by tapping it, giving the creature with bloodthirst persist until end of turn.
Activate Ashnod's Altar by sacrificing the creature with bloodthirst, adding {C}{C}.
When the creature dies, its persist ability and Dross Scorpion trigger.
Resolve the persist trigger, returning the creature from your graveyard to the battlefield, which enters the battlefield with at least one +1/+1 counter on it due to its bloodthirst ability.
Resolve the Dross Scorpion trigger, untapping Cauldron of Souls.
Repeat.

Infinite LTB

Infinite ETB

Infinite sacrifice triggers

Infinite death triggers

Infinite colorless mana

Creature with Bloodthirst

Cauldron of Souls

Dross Scorpion

Ashnod's Altar

Biotransference

Activate Cauldron of Souls by tapping it, giving the additional creatures persist until end of turn.
Activate Baba Lysaga by tapping it and sacrificing the two additional creatures.
When the creatures die, Dross Scorpion triggers twice and the creatures' persist abilities each trigger.
Resolve the Dross Scorpion triggers, untapping Baba Lysaga and Cauldron of Souls.
Resolve the first persist creature, returning one of the creatures from your graveyard to the battlefield with a -1/-1 counter on it.
When the creature enters, Thran Vigil triggers, putting a +1/+1 counter on the creature.
Repeat from step 5 for the remaining persist trigger.
Resolve the Baba Lysaga ability from step 2, causing you to gain 3 life, each opponent to lose 3 life, and you to draw three cards.
Repeat.

Infinite card draw

Near-infinite lifegain

Near-infinite lifeloss

Near-infinite lifegain triggers

Infinite draw triggers

Near-infinite LTB

Near-infinite death triggers

Near infinite ETB

Near infinite sacrifice triggers

Baba Lysaga, Night Witch

Thran Vigil

Activate Clock of Omens by tapping Emmara and another artifact, targeting Emmara.
Emmara triggers, creating a 1/1 Soldier creature token that is also an artifact due to Biotransference.
Resolve the Clock of Omens ability, untapping Emmara.
Repeat.

Infinite tapped creature tokens

Emmara, Soul of the Accord

Clock of Omens

Cast Idris either from your hand or from the command zone by paying {1}{U}{R} and commander tax, if applicable.
When Idris enters the battlefield, its imprint ability triggers, targeting Sphinx's Disciple.
Holding priority, activate Lithoform Engine's first ability by paying {2} and tapping it, copying Idris' trigger, targeting Basalt Monolith.
Resolve both Idris triggers, exiling Basalt Monolith and Sphinx's Disciple.
During your next turn, activate Idris using Basalt Monolith's first ability by tapping it, adding {C}{C}{C}.
Activate Idris using Basalt Monolith's second ability by paying {3}, untapping it.
Sphinx's Disciple triggers, causing you to draw a card.
Repeat from step 5.

Idris, Soul of the TARDIS

Lithoform Engine

Basalt Monolith

Sphinx's Disciple

Cast Idris either from your hand or from the command zone by paying {1}{U}{R} and commander tax, if applicable.
When Idris enters the battlefield, its imprint ability triggers, targeting Sphinx's Disciple.
Holding priority, activate Strionic Resonator by paying {2} and tapping it, copying Idris' trigger, targeting Basalt Monolith.
Resolve both Idris triggers, exiling Basalt Monolith and Sphinx's Disciple.
During your next turn, activate Idris using Basalt Monolith's first ability by tapping it, adding {C}{C}{C}.
Activate Idris using Basalt Monolith's second ability by paying {3}, untapping it.
Sphinx's Disciple triggers, causing you to draw a card.
Repeat from step 5.

Strionic Resonator

Deal combat damage to an opponent using Medomai the Ageless.
Medomai the Ageless triggers, causing you to take an extra turn after this one.
Cast Idris by paying {1}{U}{R}.
When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
Activate Sword of Truth and Justice's equip ability by paying {2}, attaching it to Idris.
Move to your extra turn.
At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
Deal combat damage to an opponent using Idris.
Idris and Sword of Truth and Justice trigger.
Resolve the Idris trigger, causing you to take an extra turn after this one.
Resolve the Sword of Truth and Justice trigger, putting a +1/+1 counter on a creature you control, then putting a time counter on Idris.
Repeat from step 6.

Infinite turns

Medomai the Ageless

Sword of Truth and Justice

Deal combat damage to an opponent using Medomai the Ageless.
Medomai the Ageless triggers, causing you to take an extra turn after this one.
Cast Idris by paying {1}{U}{R}.
When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
Move to your extra turn.
At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
Deal combat damage to an opponent using Idris.
Idris triggers, causing you to take an extra turn after this one.
Repeat steps 5 through 8 one additional time.
Activate Contagion Engine by paying {4} and tapping it, putting two time counters on Idris.
Repeat from step 5.

Contagion Engine

Deal combat damage to an opponent using Medomai the Ageless.
Medomai the Ageless triggers, causing you to take an extra turn after this one.
Cast Idris by paying {1}{U}{R}.
When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
Move to your extra turn.
At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
Activate Contagion Clasp by paying {4} and tapping it, putting a time counter on Idris.
Deal combat damage to an opponent using Idris.
Idris triggers, causing you to take an extra turn after this one.
Repeat from step 5.

Contagion Clasp

Deal combat damage to an opponent using Medomai the Ageless.
Medomai the Ageless triggers, causing you to take an extra turn after this one.
Cast Idris by paying {1}{U}{R}.
When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
Move to your extra turn.
At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
Deal combat damage to an opponent using Idris and Thrummingbird.
Idris and Thrummingbird trigger.
Resolve the Idris trigger, causing you to take an extra turn after this one.
Resolve the Thrummingbird trigger, putting a time counter on Idris.
Repeat from step 5.

Thrummingbird

Deal combat damage to an opponent using Medomai the Ageless.
Medomai the Ageless triggers, causing you to take an extra turn after this one.
Cast Idris by paying {1}{U}{R}.
When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
Move to your extra turn.
At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
Activate Karn's Bastion's second ability by paying {4} and tapping it, putting a time counter on Idris.
Deal combat damage to an opponent using Idris.
Idris triggers, causing you to take an extra turn after this one.
Repeat from step 5.

Karn's Bastion

Deal combat damage to an opponent using Medomai the Ageless.
Medomai the Ageless triggers, causing you to take an extra turn after this one.
Cast Idris by paying {1}{U}{R}.
When Idris enters the battlefield, it triggers, exiling Medomai the Ageless until Idris leaves the battlefield.
Activate Jhoira's Timebug by tapping it, putting a time counter on Idris.
Move to your extra turn.
At the beginning of your upkeep, Idris's vanishing ability triggers, removing a time counter from it.
Deal combat damage to an opponent using Idris.
Idris triggers, causing you to take an extra turn after this one.
Repeat from step 5.

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