Activate Feldon by paying {2}{R} and tapping it, creating a token copy of Combat Celebrant with haste.
At the beginning of your combat phase, Determined Iteration triggers, creating a token copy of the Combat Celebrant token with haste.
Declare a Combat Celebrant token as an attacker, choosing to exert it as it attacks.
The token triggers, untapping all other creatures you control and causing you to get an additional combat phase after this one.
Repeat from step 2.

Infinite combat phases

Infinite creature tokens with haste

Infinite death triggers

Infinite creature ETB

Infinite creature LTB

Infinite creature sacrifice triggers

Feldon of the Third Path

Combat Celebrant

Determined Iteration

At the beginning of your combat phase, Determined Iteration triggers, creating a creature token.
Deal combat damage using the creature that has Breath of Fury attached. Breath of Fury triggers, causing you to sacrifice the creature it is attached to, then attach Breath of Fury to the creature token, then causing you to untap all creatures you control and to get an additional combat phase after this one. 
Repeat each combat phase.

Infinite combat damage

Infinite mana creatures you control can produce

Infinite untap of creatures you control

Breath of Fury

Activate The Jolly Balloon Man by paying {1} and tapping it, creating a token copy of Combat Celebrant that is a 1/1 Balloon with flying and haste.
At the beginning of your combat phase, Determined Iteration triggers, creating a copy of the Combat Celebrant token.
Declare the Combat Celebrant token as an attacker, choosing to exert it as it attacks. It triggers, causing you to untap all other creatures you control and get an additional combat phase after this one.
Repeat from step 2 each combat phase.

The Jolly Balloon Man

At the beginning of your combat phase, Mishra and Determined Iteration trigger.
Resolve the Mishra trigger, creating a 4/4 artifact creature token copy of Gonti's Aether Heart named Mishra's Warform.
When Mishra's Warform enters the battlefield, it and Gonti's Aether Heart trigger, causing you to get four {E}.
Resolve the Determined iteration trigger, creating a token copy of the Mishra's Warform token.
When the copy of the Mishra's Warform token enters the battlefield, it, Mishra's Warform and Gonti's Aether Heart trigger, causing you to get six {E}.
Activate Mishra's Warform by paying eight {E} and exiling it, causing you to take an extra turn after this one.
Repeat each turn.

Infinite turns

Lock

Mishra, Eminent One

Gonti's Aether Heart

Activate Reflection of KIki-Jiki by paying {1} and tapping it, creating a token copy of Combat Celebrant with haste.
At the beginning of your combat phase, Determined Iteration triggers, creating a token copy of the Combat Celebrant token with haste.
Declare a Combat Celebrant token as an attacker, choosing to exert it as it attacks.
The token triggers, untapping all other creatures you control and causing you to get an additional combat phase after this one.
Repeat from step 2.

Fable of the Mirror-Breaker // Reflection of Kiki-Jiki

Activate Feldon by paying {2}{R} and tapping it, creating a token copy of Bloodthirster with haste.
At the beginning of your combat phase, Determined Iteration triggers, creating a token copy of the Bloodthirster token.
Deal combat damage with the Bloodthirster token created by Determined Iteration.
The Bloodthirster token triggers, causing you to untap it and to get an additional combat phase after this one.
Repeat from step 2.

Bloodthirster

Activate Kiki-Jiki by tapping it, creating a token copy of Bloodthirster with haste.
At the beginning of your combat phase, Determined Iteration triggers, creating a token copy of the Bloodthirster token.
Deal combat damage with the Bloodthirster token created by Determined Iteration.
The Bloodthirster token triggers, causing you to untap it and to get an additional combat phase after this one.
Repeat from step 2.

Kiki-Jiki, Mirror Breaker

Activate Jaxis by paying {R}, tapping it and discarding a card, creating a token copy of Bloodthirster with haste.
At the beginning of your combat phase, Determined Iteration triggers, creating a token copy of the Bloodthirster token.
Deal combat damage with the Bloodthirster token created by Determined Iteration.
The Bloodthirster token triggers, causing you to untap it and to get an additional combat phase after this one.
Repeat from step 2.
At the beginning of your end step, each Bloodthirster token triggers, causing you to sacrifice them.
When the tokens die, they each trigger, causing you to draw a card for each creature that dies this way.

Infinite card draw

Infinite draw triggers

Jaxis, the Troublemaker

Cast TImestream Navigator by paying {1}{U}, plus an additional {2} for its offspring cost.
If you control ten or more permanents and don't have the city's blessing, Timestream Navigator gives you the city's blessing.
When Timestream Navigator enters the battlefield, it triggers, creating a token copy of it that is 1/1.
If you control ten or more permanents and don't have the city's blessing, the Timestream Navigator token gives you the city's blessing.
At the beginning of your combat phase, Determined Iteration triggers, creating a copy of the Timestream Navigator token with haste.
If you control ten or more permanents and don't have the city's blessing, the Timestream Navigator token gives you the city's blessing.
Activate the Timestream Navigator token from step 5 by paying {2}{U}{U}, tapping it and putting it from the battlefield onto the bottom of your library, causing you to take an extra turn after this one.
Repeat steps 5 and 7 during each following turn.

Combos with "Determined Iteration"