Patron of the Moon + Tiller Engine + Boros Garrison

Patron of the Moon

Tiller Engine

Boros Garrison

How it works

1. Pay 1 to activate Patron of the Moon, putting Boros Garrison from your hand onto the battlefield.
2. When Boros Garrison enters, it and Tiller Engine each trigger.
3. Resolve Tiller Engine's ability, untapping Boros Garrison.
4. Activate Boros Garrison by tapping it, adding two mana.
5. Resolve Boros Garrison's triggered ability, returning it from the battlefield to your hand.
6. Repeat.