Activate a creature by tapping it, adding at least {U}.
Activate Harmonized Trio by tapping it and two other creatures you control, causing it to become prepared.
Cast a copy of Brainstorm by paying {U}.
Talrand triggers, creating a creature token.
When the creature token enters, Intruder Alarm triggers, untapping all creatures.
Resolve Brainstorm, causing you to draw three cards and put two cards from your hand onto the top of your library.
Repeat.

Infinite card draw

Infinite draw triggers

Near-infinite creature ETB

Near-infinite creature tokens

Near-infinite magecraft triggers

Near-infinite storm count

Near-infinite untap of all creatures

Intruder Alarm

Harmonized Trio // Brainstorm

Talrand, Sky Summoner

Cast Walk the Aeons by paying {4}{U}{U} and sacrificing a creature with power two or greater, targeting yourself.
Walk the Aeons's casualty ability and Talrand trigger.
Resolve the Walk the Aeons trigger, copying it, targeting yourself.
Resolve the Talrand trigger, creating a 2/2 Drake creature token.
Resolve both Walk the Aeonss, causing you to take two extra turns after this one.
Move to your last extra turn.
Cast Call to Mind by paying {2}{U} and sacrificing a Drake, targeting Mystic Retrieval.
Call to Mind's casualty ability and Talrand trigger.
Resolve the Call to Mind trigger, copying it, targeting Walk the Aeons.
Resolve the Talrand trigger, creating a 2/2 Drake creature token.
Resolve both Call to Minds, returning Walk the Aeons and Mystic Retrieval from your graveyard to your hand.
Repeat steps 1 through 6 one additional time.
Cast Mystic Retrieval by paying {3}{U} and sacrificing a Drake, targeting Call to Mind.
Mystic Retrieval's casualty ability and Talrand trigger.
Resolve the Mystic Retrieval trigger, copying it, targeting Walk the Aeons.
Resolve the Talrand trigger, creating a 2/2 Drake creature token.
Resolve both Mystic Retrievals, returning Walk the Aeons and Call to Mind from your graveyard to your hand.
Repeat steps 1 through 6 one additional time.
Repeat from step 7.

Infinite turns

Lock

Anhelo, the Painter

Call to Mind

Mystic Retrieval

Walk the Aeons

Activate The Tenth Doctor by paying {7}, removing all time counters from Reality Strobe.
Reality Strobe triggers, causing you to cast it from exile without paying its mana cost.
Talrand triggers, creating a creature token.
When the creature token enters, Mana Echoes triggers, adding {C} for each creature you control that shares a creature type with the token.
Resolve Reality Strobe.
Repeat.

Infinite creature ETB

Infinite colorless mana

Infinite creature tokens

Infinite magecraft triggers

Mass Land Denial

Return any number of permanents to their owner's hand

The Tenth Doctor

Mana Echoes

Reality Strobe

Activate Spellbinding Soprano's encore ability by paying {3}{R} and exiling it from your graveyard, creating a token copy of it with haste for each opponent you have.
Declare each Spellbinding Soprano token as an attacker.
Each Spellbinding Soprano token triggers, causing instant and sorcery spells you cast this turn to cost {1} less to cast for each Spellbinding Soprano token.
Cast Sprout Swarm with buyback by tapping a green creature and any other creature you control.
Talrand's first ability triggers, creating a 2/2 Drake creature token.
Resolve Sprout Swarm, creating a 1/1 Saproling creature token and returning Sprout Swarm to your hand.
Repeat from step 4.

Infinite storm count

Infinite tapped creature tokens

Spellbinding Soprano

Sprout Swarm

Combos with "Talrand, Sky Summoner"