Mikaeus, the Unhallowed + Ashnod's Altar + Wingrattle Scarecrow

Mikaeus, the Unhallowed

Ashnod's Altar

Wingrattle Scarecrow

How it works

1. Activate Ashnod's Altar by sacrificing Wingrattle Scarecrow.
2. When Wingrattle Scarecrow dies, its persist ability triggers, returning it from your graveyard to the battlefield with a -1/-1 counter on it.
3. Activate Ashnod's Altar by sacrificing Wingrattle Scarecrow.
4. When Wingrattle Scarecrow dies, its undying ability triggers, returning it from your graveyard to the battlefield with a +1/+1 counter on it.
5. Repeat.

This ingenious loop relies on a clever mechanical interaction between opposing counter types to endlessly recycle a single automaton. By sacrificing Wingrattle Scarecrow to Ashnod's Altar, you generate a steady stream of colorless mana while sending the Scarecrow to the graveyard. The true engine, however, is Mikaeus, the Unhallowed: his static ability grants undying to your non-Human creatures, while the Scarecrow's own persist ability brings it back when it dies without a -1/-1 counter. Because the +1/+1 counter from undying and the -1/-1 counter from persist continually cancel each other out upon subsequent deaths, the Scarecrow can alternate between dying with a -1/-1 counter and dying with a +1/+1 counter indefinitely, fueling an endless cascade of sacrifice triggers and mana.