Magar of the Magic Strings + Final Fortune + Day's Undoing

Magar of the Magic Strings

Final Fortune

Day's Undoing

How it works

1. Cast Final Fortune 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. Activate Magar by paying 1, noting Final Fortune and putting it face down on the battlefield as a 3/3 creature.
3. Activate Magar by paying 1, noting Day's Undoing and putting it face down on the battlefield as a 3/3 creature.
4. During your next turn, deal combat damage to an opponent using the face down creatures that have Final Fortune and Day's Undoing noted. The creatures trigger.
5. Resolve the first trigger, casting a copy of Final Fortune 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. Resolve 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 Final Fortune trigger from causing you to lose the game.
7. Repeat from step 3.

This clever loop turns Magar of the Magic Strings into a literal story generator by turning your graveyard's most dangerous spells into 3/3 combat threats. When those face-down creatures successfully connect with an opponent, Magar lets you cast copies of the noted cards for free, starting with Final Fortune to chain extra turns indefinitely. Because Final Fortune comes with a game-losing delayed trigger at the end step, you also trigger a copy of Day's Undoing during the same combat damage step to abruptly end the turn, bypassing your end step entirely and wiping away the loss condition before it can ever collect its toll.