Promised Kannushi + Arcane Adaptation + Ashnod's Altar + Signpost Scarecrow

Promised Kannushi

Arcane Adaptation

Ashnod's Altar

Signpost Scarecrow

How it works

1. Activate Ashnod's Altar by sacrificing Promised Kannushi, adding CC.
2. When Promised Kannushi dies, its soulshift ability triggers, returning itself from your graveyard to your hand.
3. Activate Signpost Scarecrow by paying 2, adding .
4. Cast Promised Kannushi by paying .
5. Repeat.

By setting Arcane Adaptation to name Spirits, we transform Promised Kannushi into a Spirit card even while it sits waiting in our hand, allowing its own Soulshift 7 ability to target itself when it dies. Once it hits the graveyard, Ashnod's Altar provides the exact pair of colorless mana we need to sacrifice it over and over, while Signpost Scarecrow filters that raw mana into the single green pip required to recast the Kannushi. Because the looping creature keeps returning directly to your hand and recasting for just one mana, you generate an endless storm of sacrifices, enters-the-battlefield triggers, and deaths.