Magar of the Magic Strings, Warrior's Oath, and Sundial of the Infinite

Prerequisites

• Magar of the Magic Strings on the battlefield
• Warrior's Oath in hand
• Sundial of the Infinite on the battlefield
• 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 Sundial of the Infinite by paying and tapping it, ending the turn
9. Repeat from step 3

Results

• Infinite turns