Requires

Halo Fountain must be on the battlefield. Aphetto Alchemist must be on the battlefield. Phyrexian Altar must be on the battlefield. Aphetto Alchemist does not have summoning sickness. Mana needed:

Steps

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

Results