Zinnia, Valley's Voice, Timestream Navigator, and Riptide Laboratory

Prerequisites

• Zinnia, Valley's Voice on the battlefield
• Timestream Navigator in hand
• Riptide Laboratory on the battlefield
• available the first turn, with each following turn available

Steps

1. Cast TImestream Navigator by paying , plus an additional for its offspring cost
2. If you control ten or more permanents and don't have the city's blessing, Timestream Navigator gives you the city's blessing
3. When Timestream Navigator enters the battlefield, it triggers, creating a token copy of it that is 1/1
4. If you control ten or more permanents and don't have the city's blessing, the Timestream Navigator token gives you the city's blessing
5. Activate Riptide Laboratory by paying and tapping it, returning the nontoken Timestream Navigator from the battlefield to your hand
6. During your next turn, repeat steps 1 through 5 one additional time
7. Activate the oldest Timestream Navigator token by paying , tapping it and putting it from the battlefield onto the bottom of your library, causing you to take an extra turn after this one
8. Repeat from step 8

Results

• Infinite turns