Mikaeus, the Unhallowed + Antler Skulkin + Phyrexian Altar

Mikaeus, the Unhallowed

Antler Skulkin

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing the nontoken, non-Human white creature, adding 1.
2. When the creature dies, its undying ability triggers, returning it to the battlefield from your graveyard with a +1/+1 counter on it.
3. Activate Antler Skulkin by paying 2, giving the creature persist until end of turn.
4. Activate Phyrexian Altar by sacrificing the creature, adding 1.
5. When the creature dies, its persist ability triggers, returning it to the battlefield from your graveyard with a -1/-1 counter on it.
6. Repeat.

This clever loop relies on counter cancellation to recycle your resources indefinitely. By utilizing Mikaeus, the Unhallowed to grant undying to a non-Human white creature, you can sacrifice it to Phyrexian Altar for mana; when it returns with a +1/+1 counter, Antler Skulkin steps in to grant it persist. Sacrificing the creature again triggers its persist ability to return it with a -1/-1 counter, which immediately annihilates the lingering +1/+1 counter through state-based actions. Because the creature is now entirely free of counters once more, its undying ability is primed to trigger on the next sacrifice, letting you repeat this beautiful cycle infinitely.