Cast Ashling's Command by paying {U}{R} due to Font of Magic. Choose its fourth mode targeting yourself and then any other mode as desired.
Holding priority, cast Reiterate with buyback by paying {R}{R} due to Font of Magic, copying Ashling's Command with the fourth mode targeting yourself and returning Reiterate to your hand.
Resolve the copy of Ashling's Command, creating two Treasure tokens and performing the action of the other chosen mode.
Holding priority, activate the Treasures by tapping and sacrificing them, adding {R}{R}.
Repeat from step 2.

Infinite ETB

Infinite storm count

Infinite creature tokens

Infinite magecraft triggers

Infinite card draw for any number of players

Infinite draw triggers for any number of players

Infinite token copies of Elementals you control

Ashling's Command

Reiterate

Font of Magic

Activate an animated land by tapping it, adding at least {U}.
Cast View from Above by paying {U}, targeting the animated land.
Orvar triggers, creating a token copy of the animated land that is not a creature.
Resolve View from Above, returning it to your hand.
Activate the land token by tapping it, adding at least {U}.
Repeat from step 2.

Infinite landfall triggers

Infinite tapped Island tokens

Card That Animates a Land

Orvar, the All-Form

View from Above

Cast Mystic Speculation by paying {U} due to Font of Magic.
Namor triggers, creating a 1/1 Merfolk creature token.
Resolve Mystic Speculation.
Activate Phyrexian Altar by sacrificing the Merfolk, adding {U}.
Repeat.

Infinite LTB

Infinite death triggers

Infinite sacrifice triggers

Infinite scry

Namor the Sub-Mariner

Phyrexian Altar

Mystic Speculation

Cast Clockspinning with buyback by paying {U} due to Font of Magic, putting a +1/+1 counter on Berta and returning Clockspinning to your hand.
Berta triggers, adding {U}.
Repeat.

Infinite +1/+1 counters on a creature

Berta, Wise Extrapolator

Clockspinning

Activate Kiki-Jiki by tapping it, copying Blazing Firesinger. It'll enter prepared due to its effect.
Cast a copy of Seething Song by paying at most {1}{R} due to Font of Magic.
Hematite Talisman triggers, causing you to pay {3} to untap Kiki-Jiki.
Resolve Seething Song, adding {R}{R}{R}{R}{R}.
Repeat.

Infinite creature tokens with haste

Infinite red mana

Kiki-Jiki, Mirror Breaker

Blazing Firesinger // Seething Song

Hematite Talisman

At the beginning of your precombat main phase, Summon: Esper Valigarmanda triggers, putting a lore counter on it and triggering its fourth chapter ability.
Holding priority, cast Clockspinning with buyback by paying {1}, removing a lore counter from Summon: Esper Valigarmanda and returning Clockspinning to your hand.
Resolve the Summon: Esper Valigarmanda ability, adding {R}{R}{R}.
Cast Clockspinning with buyback by paying {1}, putting a lore counter on Summon: Esper Valigarmanda and returning Clockspinning to your hand.
Summon: Esper Valigarmanda's fourth chapter ability triggers.
Repeat from step 2.

Infinite colored mana

Infinite colorless mana

Infinite proliferate

Summon: Esper Valigarmanda

Mycosynth Lattice

Cast a copy of Seething Song from exile by paying no more than {1}{R}, adding {R}{R}{R}{R}{R}.
Activate Emiel the Blessed by paying {3}, blinking Blazing Firesinger, which enters prepared.
Repeat.

Infinite blinking

Emiel the Blessed

Cast Nameless Inversion from your graveyard, as it is a Knight card, by paying {0} due to Font of Magic and Morophon, giving a creature +3/-3 until end of turn.
If the creature has toughness 0 or less, the creature dies as a state-based action.
Repeat as desired.

Combos with "Font of Magic"