Mikaeus, the Unhallowed + Ashcloud Phoenix + Ashnod's Altar

Mikaeus, the Unhallowed

Ashcloud Phoenix

Ashnod's Altar

How it works

1. Activate Ashnod's Altar by sacrificing Ashcloud Phoenix, adding CC.
2. When Ashcloud Phoenix dies, it triggers, as well as its undying ability if it does not have a +1/+1 counter on it.
3. Resolve the first trigger, returning it from your graveyard to the battlefield face-down.
4. Resolve the second trigger, doing nothing.
5. Activate Ashnod's Altar by sacrificing Ashcloud Phoenix, adding CC.
6. When Ashcloud Phoenix dies, it triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
7. Repeat.