Requires

Lagrella, the Magpie must be in hand, or in the command zone. Sun Titan must be on the battlefield. Phyrexian Altar must be on the battlefield. Mana needed: plus enough mana to pay for commander tax, if applicable

Steps

1. Cast Lagrella by paying and commander tax, if applicable.
2. When Lagrella enters the battlefield, it triggers, exiling Sun Titan until Lagrella leaves the battlefield.
3. Activate Phyrexian Altar by sacrificing Lagrella, adding one mana of any color.
4. If Lagrella is your commander, choose not to return it to the command zone from your graveyard.
5. When Lagrella leaves the battlefield, Sun Titan is returned to the battlefield from exile.
6. When Sun Titan enters the battlefield, it and Lagrella triggers.
7. Resolve the Lagrella trigger, putting two +1/+1 counters on Sun Titan.
8. Resolve the Sun Titan trigger, returning Lagrella from your graveyard to the battlefield.
9. Repeat from step 2.

Results