Mikaeus, the Unhallowed + Otherworldly Escort + Phyrexian Altar

Mikaeus, the Unhallowed

Otherworldly Escort

Phyrexian Altar

How it works

1. Activate Phyrexian Altar by sacrificing Otherworldly Escort.
2. When Otherworldly Escort dies, it triggers, returning itself from your graveyard to the battlefield as a Spirit Detective.
3. Resolve the Phyrexian Altar ability.
4. Activate Phyrexian Altar by sacrificing Otherworldly Escort.
5. When Otherworldly Escort dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
6. Repeat.

This clever loop hinges on the clever interaction between Otherworldly Escort and the static lord ability granted by Mikaeus, the Unhallowed. When you sacrifice Otherworldly Escort to Phyrexian Altar for a shot of mana, its own death trigger returns it as a Spirit with charge counters, stripping away the Human type so Mikaeus's undying buff can subsequently apply. The next time it hits the altar, Mikaeus steps in to grant it undying, bringing it right back with a +1/+1 counter and setting up an alternating cycle of resurrection. Because Otherworldly Escort perpetually toggles between its own revival mechanic and Mikaeus's undying, you can infinitely sacrifice it to Phyrexian Altar to churn out infinite mana and a storm of death and entry triggers.