Teshar, Ancestor's Apostle + Scrap Trawler + Grinding Station + Dark Sphere

Teshar, Ancestor's Apostle

Scrap Trawler

Grinding Station

Dark Sphere

How it works

1. Cast Dark Sphere by paying its mana cost.
2. Teshar triggers, returning Scrap Trawler from your graveyard to the battlefield.
3. When Scrap Trawler and Dark Sphere enter, Grinding Station triggers twice, untapping Grinding Station.
4. Activate Dark Sphere by tapping and sacrificing it.
5. Activate Grinding Station by tapping it and sacrificing Scrap Trawler.
6. When Scrap Trawler dies, it triggers, returning Dark Sphere from your graveyard to your hand.
7. Resolve the Grinding Station ability.
8. Repeat.