Cast Nature's Rhythm either from your hand or graveyard by paying at most {4}{G}{G}{G}{G}, searching your library for Felidar Guardian and putting it onto the battlefield.
When Felidar Guardian enters, Felidar Guardian and Preston trigger.
Resolve the Felidar Guardian trigger, blinking another permanent you control.
Resolve the Preston trigger, creating a token copy of Felidar Guardian that is a 0/1 Illusion.
When the Felidar Guardian token enters the battlefield, it triggers, blinking the nontoken Felidar Guardian.
Repeat from step 2.

Exile all nonland permanents opponents control

Infinite creature ETB

Infinite creature LTB

Infinite blinking of permanents

Infinite creature tokens

Infinite landfall triggers

Infinite mana lands you control can produce

Infinite mana lands you control that enter the battlefield untapped can produce

Preston, the Vanisher

Felidar Guardian

Nature's Rhythm

Cast Nature's Rhythm from your hand by paying {5}{G}{G} or from your graveyard for its harmonize cost by paying at most {5}{G}{G}{G}{G}, searching your library for Karmic Guide and putting it onto the battlefield.
When Karmic Guide enters, it and Preston trigger.
Resolve the Karmic Guide trigger, returning an applicable target from your graveyard to the battlefield.
Holding priority, activate Ashnod's Altar by sacrificing Karmic Guide.
Resolve the Preston trigger, creating a token copy of Karmic Guide that is a 0/1 Illusion.
When the Karmic Guide token enters, it triggers, returning Karmic Guide from your graveyard to the battlefield.
Repeat from step 2.

Infinite colorless mana

Infinite death triggers

Infinite recursion of creature cards in your graveyard

Infinite creature sacrifice triggers

Ashnod's Altar

Karmic Guide

Cast Nature's Rhythm by paying at most {3}{G}{G}{G}{G}, searching your library for Fiend Hunter and putting it onto the battlefield.
When Fiend Hunter enters, it and Preston trigger.
Resolve the Fiend Hunter trigger, exiling another creature if needed.
Resolve the Preston trigger, creating a token copy of Fiend Hunter that is a 0/1 Illusion.
When the Fiend Hunter token enters, it triggers, exiling the nontoken Fiend Hunter.
Activate Ashnod's Altar by sacrificing the Fiend Hunter token
When the Fiend Hunter token dies, it triggers, returning Fiend Hunter from exile to the battlefield.
Repeat from step 2.

Fiend Hunter

Combos with "Nature's Rhythm"