Halo Fountain + Clever Conjurer + Phyrexian Altar

Halo Fountain

Clever Conjurer

Phyrexian Altar

How it works

1. Activate Clever Conjurer by tapping it, targeting Halo Fountain.
2. Holding priority, activate Halo Fountain's first ability by paying , tapping it and untapping Clever Conjurer, creating a 1/1 Citizen creature token.
3. Resolve the Clever Conjurer ability, untapping Halo Fountain.
4. Activate Phyrexian Altar by sacrificing the Citizen token, adding .
5. Repeat.