Magar of the Magic Strings + Warrior's Oath + Day's Undoing

Prerequisites

• An opponent cannot block creatures you control.

Steps

1. 1Cast Warrior's Oath by paying its mana cost, causing you to take an extra turn after this one and to lose the game at the beginning of that turn's end step.
2. 2Activate Magar by paying , noting Warrior's Oath and putting it face down on the battlefield as a 3/3 creature.
3. 3Activate Magar by paying , noting Day's Undoing and putting it face down on the battlefield as a 3/3 creature.
4. 4During your next turn, deal combat damage to an opponent using the face down creatures that have Warrior's Oath and Day's Undoing noted. The creatures trigger.
5. 5Resolve the first trigger, casting a copy of Warrior's Oath without paying its mana cost. Resolve the copy, causing you to take an extra turn after this one and to lose the game at the beginning of that turn's end step.
6. 6Resolve the second trigger, casting a copy of Day's Undoing without paying its mana cost. Resolve the copy, causing you to end the turn. This will prevent the Warrior's Oath trigger from causing you to lose the game.
7. 7Repeat from step 3.

Effects

• Infinite turns
• Lock