Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Phyrexian Altar + Propeller Pioneer

Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight

Phyrexian Altar

Propeller Pioneer

How it works

1. Activate Phyrexian Altar by sacrificing Propeller Pioneer.
2. When Propeller Pioneer dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. When Propeller Pioneer enters, its fabricate ability triggers, putting a +1/+1 counter on it.
4. Repeat.