Eirdu, Carrier of Dawn // Isilu, Carrier of Twilight + Phyrexian Altar + Virtuous Variant

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

Phyrexian Altar

Virtuous Variant

How it works

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