Mikaeus, the Unhallowed + Cryptic Trilobite + Ashnod's Altar

Mikaeus, the Unhallowed

Cryptic Trilobite

Ashnod's Altar

How it works

1. If Cryptic Trilobite has any +1/+1 counters, activate Cryptic Trilobite's first activated ability until it has no +1/+1 counters, adding CC that can only be spent to activate abilities each time.
2. Activate Ashnod's Altar by sacrificing Cryptic Trilobite, adding CC.
3. Cryptic Trilobite's undying ability from Mikaeus triggers, returning Cryptic Trilobite from your graveyard to the battlefield with a +1/+1 counter on it.
4. Repeat.