Scouring Swarm + Drownyard Temple + Phyrexian Altar + Overgrown Estate

Scouring Swarm

Drownyard Temple

Phyrexian Altar

Overgrown Estate

How it works

1. Activate Overgrown Estate by sacrificing Drownyard Temple.
2. Each Scouring Swarm you control triggers, creating a tapped token copy of itself.
3. Resolve the Overgrown Estate ability.
4. If you control four or more Scouring Swarms, activate Phyrexian Altar by sacrificing a Scouring Swarm, adding 1.
5. Repeat step 4 until you control three Scouring Swarms or until you have 3 available, whichever comes first.
6. Activate Drownyard Temple by paying 3, returning it from your graveyard to the battlefield.
7. Repeat.

This clever loop turns the self-recurring nature of Drownyard Temple into a self-sustaining engine, utilizing Overgrown Estate as a convenient way to sacrifice the land straight into your graveyard. Once you have at least seven land cards in your graveyard, the replacement clause on Scouring Swarm turns every land sacrifice into a duplicated army of flying threats. Phyrexian Altar then acts as the crucial mana-producing valve, letting you harvest your extra insect copies for the exact colored mana needed to pull Drownyard Temple right back onto the battlefield.