Timestream Navigator + Gravecrawler + Birthing Pod

Timestream Navigator

Gravecrawler

Birthing Pod

How it works

1. Activate 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.
2. Activate Birthing Pod by paying 1G/P, tapping it and sacrificing Gravecrawler, causing you to search your library for Timestream Navigator and put it onto the battlefield.
3. Cast Gravecrawler from your graveyard by paying .
4. Repeat each turn.

This ingenious loop is fueled by Timestream Navigator's activated ability, which grants you an extra turn by tucking itself onto the bottom of your library, provided you have the city's blessing. To pull this off repeatedly, you use Birthing Pod to sacrifice Gravecrawler—which easily casts itself right back out of your graveyard as long as you control a Zombie—to fetch the Navigator straight from your library onto the battlefield. By taking advantage of the extra turn to reset and repeat the process, you secure infinite turns and lock your opponents out of the game entirely.