Obeka, Brute Chronologist, Magar of the Magic Strings, and Warrior's Oath

Prerequisites

• Obeka, Brute Chronologist on the battlefield
• Magar of the Magic Strings on the battlefield
• Warrior's Oath in hand
• An opponent is unable to block and kill creatures you control
• available

Steps

1. Cast Warrior's Oath by paying , causing you to take an extra turn after this one
2. Activate Magar by paying , noting Warrior's Oath and putting it face down as a 3/3 creature
3. Move to your next turn
4. Deal combat damage to an opponent with the face down creature
5. The face down creature triggers, causing you to cast a copy of Warrior's Oath without paying its mana cost
6. Resolve the copy of Warrior's Oath, causing you to take an extra turn after this one
7. At the beginning of your end step, Warrior's Oath triggers
8. Holding priority, activate Obeka by tapping it, ending the turn
9. Repeat from step 3

Results

• Infinite turns