Urza, Prince of Kroog + Timestream Navigator + Liquimetal Coating

Urza, Prince of Kroog

Timestream Navigator

Liquimetal Coating

How it works

1. Activate Liquimetal Coating by tapping it, causing Timestream Navigator to become an artifact until end of turn.
2. Activate Urza by paying 6, creating a token copy of Timestream Navigator that is a 1/1 Soldier creature.
3. 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.
4. Repeat each turn.