Emeria Shepherd + Wormfang Newt + Phyrexian Altar

Emeria Shepherd

Wormfang Newt

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing Wormfang Newt, adding one mana of any color.
2. When Wormfang Newt dies, its second ability triggers, returning a Plains from exile to the battlefield.
3. When the Plains enters the battlefield, Emeria Shepherd triggers.
4. Holding priority, activate the Plains by tapping it, adding .
5. Resolve the Emeria Shepherd trigger, returning Wormfang Newt from your graveyard to the battlefield.
6. When Wormfang Newt enters the battlefield, its first ability triggers, exiling a Plains.
7. Repeat.