Azusa, Lost but Seeking + Magistrate's Scepter + Evolution Sage + Boros Garrison

Azusa, Lost but Seeking

Magistrate's Scepter

Evolution Sage

Boros Garrison

How it works

1. Play Boros Garrison.
2. When Boros Garrison enters the battlefield, it and Evolution Sage trigger.
3. Resolve the Boros Garrison trigger, returning it from the battlefield to your hand.
4. Resolve the Evolution Sage trigger, putting a charge counter on Magistrate's Scepter.
5. Repeat from step 1 until Magistrate's Scepter has four or more charge counters on it.
6. Activate Magistrate's Scepter's second ability by tapping it and removing three charge counters from it, causing you to take an extra turn after this one.
7. Repeat each turn.