Scouring Swarm + Drownyard Temple + Ashnod's Altar + Sylvan Safekeeper

Scouring Swarm

Drownyard Temple

Ashnod's Altar

Sylvan Safekeeper

How it works

1. Activate Sylvan Safekeeper by sacrificing Drownyard Temple.
2. Each Scouring Swarm you control triggers, creating a tapped token copy of itself.
3. Resolve the Sylvan Safekeeper ability.
4. If you control four or more Scouring Swarms, activate Ashnod's Altar by sacrificing a Scouring Swarm, adding .
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 engine uses Sylvan Safekeeper to feed Drownyard Temple directly into your graveyard as a deliberate sacrifice. Once your graveyard holds seven or more land cards, Scouring Swarm triggers off that sacrifice to multiply itself into an army of flying copies. You can then turn those extra insects into fuel for Ashnod's Altar, generating a surplus of colorless mana to pay Drownyard Temple's resurrection cost and loop the whole process indefinitely.