The Master, Multiplied + Kiki-Jiki, Mirror Breaker + Izzet Chemister + Time Stretch

The Master, Multiplied

Kiki-Jiki, Mirror Breaker

Izzet Chemister

Time Stretch

How it works

1. Cast Time Stretch by paying 8, causing you to take two extra turns after this one.
2. Activate Kiki-Jiki by tapping it, creating a token copy of Izzet Chemister.
3. Activate the Izzet Chemister token's first ability by paying and tapping it, exiling Time Stretch from your graveyard.
4. At the beginning of your end step, Kiki-Jiki triggers, but you cannot sacrifice the Izzet Chemister token due to The Master.
5. On your next turn, activate the Izzet Chemister token's last ability by paying 1, tapping it, and sacrificing it, casting the exiled spell without paying its mana cost.
6. Resolve that spell, causing you to take two extra turns after this one.
7. Repeat from step 2 (note that you can divide these steps among your multiple extra turns to reduce the minimum mana required to the amount shown in the prerequisites).

This clever loop harnesses Kiki-Jiki, Mirror Breaker to repeatedly clone Izzet Chemister, letting you exile and recast Time Stretch turn after turn for infinite extra turns. The real genius here lies in The Master, Multiplied: its static ability prevents you from ever having to sacrifice or exile your creature tokens, allowing the Izzet Chemister token to safely dodge Kiki-Jiki's mandatory end-step sacrifice so it stays on the battlefield ready to launch your next time warp.