Magar of the Magic Strings, Brass's Bounty, and Time Sieve

Prerequisites

• Magar of the Magic Strings on the battlefield
• Brass's Bounty in the graveyard
• Time Sieve on the battlefield
• An opponent is unable to block and kill creatures you control
• You control at least five lands
• available

Steps

1. Activate Magar by paying , noting Brass's Bounty and putting it face down as a 3/3 creature
2. On any other turn, deal combat damage to an opponent with the face down creature
3. The face down creature triggers, causing you to cast a copy of Brass's Bounty without paying its mana cost
4. Resolve the copy of Brass's Bounty, creating at least five Treasure tokens
5. Activate Time Sieve by tapping and sacrificing five Treasures, causing you to take an extra turn after this one
6. Repeat from step 2

Results

• Infinite turns