At the beginning of your end step, Artificer Class's level 3 ability triggers, creating a token copy of Worldwalker Helm plus a Map token
Activate Urza's first ability twice by tapping a Worldwaker Helm and a Map, adding {U}{U}.
Activate a Worldwalker Helm by paying {1}{U} and tapping it, creating a token copy of the Worldwalker Helm token plus a Map token for each Worldwalker Helm you control.
Activate Urza's first ability twice by tapping two Maps, adding {U}{U}.
Repeat from step 3.

Infinite artifact tokens

Infinite blue mana

Exile your library

Cast all spells in your library

Infinite Map tokens

Urza, Lord High Artificer

Worldwalker Helm

Artificer Class

At the beginning of your end step, Artificer Class triggers, creating a token copy of Myr Battlesphere.
The Myr Battlesphere token enters the battlefield, creating four 1/1 Myr creature tokens.
Activate Time Sieve by tapping it, sacrificing the Myr Battlesphere token and sacrificing the four Myr tokens, causing you to take an extra turn after this one.
Repeat each turn.

Infinite turns

Lock

Time Sieve

Myr Battlesphere

At the beginning of your end step, Artificer Class triggers, creating a token copy of Basalt Monolith.
Activate the token Basalt Monolith's first ability by tapping it, adding {C}{C}{C}.
Roxanne's second ability triggers, adding {C}.
Activate the token Basalt Monolith's second ability by paying {3}, untapping it.
Repeat from step 2.

Infinite colorless mana

Roxanne, Starfall Savant

Basalt Monolith

At the beginning of your end step, Artificer Class triggers, creating a token copy of Ugin's Nexus.
Put the token Ugin's Nexus into exile due to the legend rule, causing you to take an extra turn after this one.
Repeat each turn.

Ugin's Nexus

Tamiyo's Compleation

Cast View from Above by paying {1}{U}.
Birgi and Saheeli trigger.
Resolve the Birgi trigger, adding {R}.
Resolve the Saheeli trigger, creating a 1/1 Servo artifact creature token.
Resolve View from Above, returning it to your hand.
Activate the Servo by tapping it, adding {U} that can only be spent to cast an instant or sorcery spell, or to gain a Class level.
Repeat.

Infinite artifact ETB

Infinite creature ETB

Infinite storm count

Infinite magecraft triggers

Infinite tapped creature tokens

Birgi, God of Storytelling // Harnfel, Horn of Bounty

Saheeli, Sublime Artificer

View from Above

Sorcerer Class

Frostcliff Siege

Cast View from Above by paying {1}{U}.
Urabrask and Saheeli trigger.
Resolve the Urabrask trigger, adding {R} and dealing 1 damage to an opponent.
Resolve the Saheeli trigger, creating a 1/1 Servo artifact creature token.
Resolve View from Above, returning it to your hand.
Activate the Servo by tapping it, adding {U} that can only be spent to cast an instant or sorcery spell, or to gain a Class level.
Repeat.

Infinite damage

Urabrask // The Great Work

At the beginning of your end step, Artificer Class triggers, creating a token copy of Genesis Chamber.
During your next turn, cast Emry from the command zone by paying {U}.
When Emry enters the battlefield, it and both Genesis Chambers trigger.
Resolve the Emry trigger, causing you to mill four cards.
Resolve both Genesis Chamber triggers, creating two 1/1 Myr artifact creature tokens.
Activate Phyrexian Altar by sacrificing Emry, adding {U}.
Choose to return Emry to the command zone from your graveyard.
Repeat from step 2.

Infinite creature LTB

Infinite colored mana

Infinite creature sacrifice triggers

Infinite death triggers

Infinite creature tokens

Infinite commander casts

Infinite self-mill

Emry, Lurker of the Loch

Phyrexian Altar

Genesis Chamber

At the beginning of your combat phase, Mishra triggers, creating a token copy of Worldwalker Helm that is a 4/4 Construct artifact creature with haste named Mishra's Warform, and a Map token.
Activate Urza's first ability by tapping a Map, adding {U}.
Activate Mishra's Warform by paying {1}{U} and tapping it, creating a token copy of it and a Map token for each Mishra's Warform and/or Worldwalker Helm you control.
Activate Urza's first ability twice by tapping two Maps, adding {U}{U}.
Repeat from step 3.

Mishra, Eminent One

Barbarian Class

Cast Ugin's Nexus by paying {5}.
At the beginning of your end step, Phenomenon Investigators and Artificer Class trigger.
Resolve the Artificer Class trigger, creating a token copy of Ugin's Nexus.
Put the token Ugin's Nexus into exile due to the legend rule and the token's replacement effect, causing you to take an extra turn after this one.
Resolve the Phenomenon Investigators trigger, returning Ugin's Nexus from the battlefield to your hand and causing you to draw a card.
Repeat during each of your turns.

Phenomenon Investigators

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