Urza, Prince of Kroog + Timestream Navigator + Thran Forge
How it works
- Activate Thran Forge by paying 2, causing Timestream Navigator to get +1/+0 and become an artifact until end of turn.
- Activate Urza by paying 6, creating a token copy of Timestream Navigator that is a 1/1 Soldier creature.
- Activate the oldest Timestream Navigator by paying 2, tapping it and putting it on the bottom of your library from the battlefield, causing you to take an extra turn after this one.
- Repeat each turn.
This clever engine turns a Merfolk Wizard into a permanent fixture of your extra-turn loop by leaning into type-changing and token replication. With the city's blessing active, Timestream Navigator normally shuffles away to the bottom of your library after granting you an extra turn, but Urza, Prince of Kroog bypasses this restriction by using its hefty mana ability to forge a 1/1 token copy of the Navigator. Because Timestream Navigator is a nonartifact creature, it relies on Thran Forge's targeted activation to temporarily become an artifact, making it a valid target for Urza's copying magic. By cycling through your turns and repeatedly sacrificing the original to its own ability while keeping the token safe, you secure infinite turns and lock the game down completely.