Kaya's Ghostform + Salvaging Station + Encroaching Mycosynth + Bile Urchin

Kaya's Ghostform

Salvaging Station

Encroaching Mycosynth

Bile Urchin

How it works

1. Activate Bile Urchin by sacrificing it.
2. Bile Urchin dies, triggering Salvaging Station and Kaya's Ghostform.
3. Resolve the Salvaging Station trigger, untapping it.
4. Resolve the Kaya's Ghostform trigger, returning Bile Urchin from your graveyard to the battlefield.
5. Resolve the Bile Urchin ability from step 1, causing target player to lose 1 life.
6. Activate Salvaging Station by tapping it, returning Kaya's Ghostform from your graveyard to the battlefield attached to Bile Urchin.
7. Repeat.