Osgir, the Reconstructor + Ugin's Nexus + Mirror of Fate + Codex Shredder

Prerequisites

• Osgir does not have summoning sickness.
• You have at least one card in exile.

Steps

1. 1Activate Osgir's second ability by paying , tapping it and exiling Ugin's Nexus from your graveyard, creating two token copies of Ugin's Nexus.
2. 2Exile one of the Ugin's Nexus copies due to the legend rule, causing you to take an extra turn after this one.
3. 3Activate Osgir's first ability by paying and sacrificing the remaining Ugin's Nexus token.
4. 4The Ugin's Nexus token is exiled instead of being put into your graveyard, causing you to take an extra turn after this one.
5. 5Resolve the Osgir ability, giving a creature you control +2/+0 until end of turn.
6. 6Move to your first extra turn.
7. 7If you do not control a Mirror of Fate token, activate Osgir's second ability by paying , tapping it and exiling Mirror of Fate from your graveyard, creating two token copies of Mirror of Fate.
8. 8Activate a Mirror of Fate token by tapping and sacrificing it, choosing Ugin's Nexus, any other card in exile, Mirror of Fate and up to four other cards in exile, then exiling your library and putting the chosen cards on top in the aforementioned order.
9. 9Activate Codex Shredder's first ability by tapping it, causing you to mill Ugin's Nexus.
10. 10Move to your second extra turn.
11. 11Activate Codex Shredder's first ability by tapping it, causing you to mill Mirror of Fate.
12. 12Repeat.

Effects

• Infinite turns
• Lock