Patron of the Moon + Selesnya Sanctuary + Horizon Explorer

Patron of the Moon

Selesnya Sanctuary

Horizon Explorer

How it works

1. Pay 1 to activate Patron of the Moon, putting Selesnya Sanctuary from your hand onto the battlefield untapped due to Horizon Explorer.
2. When Selesnya Sanctuary enters, it triggers.
3. Activate Selesnya Sanctuary by tapping it, adding two mana.
4. Resolve Selesnya Sanctuary's triggered ability, returning it from the battlefield to your hand.
5. Repeat.