Aetheric Amplifier + Teferi, Master of Time

Steps

1. Activate Aetheric Amplifier by paying {4} and tapping it, doubling the loyalty counters on Teferi.
2. Activate Teferi's third loyalty ability by removing ten loyalty counters from it, causing you to take two extra turns after this one.
3. Move to your first extra turn.
4. Activate Teferi's first loyalty ability by putting a loyalty counter on it, causing you to loot.
5. Activate Aetheric Amplifier by paying {4} and tapping it, doubling the loyalty counters on Teferi.
6. Move to your second extra turn and repeat.