Urtet, Remnant of Memnarch + Ashnod's Altar + Scrap Trawler + Myr Retriever

Urtet, Remnant of Memnarch

Ashnod's Altar

Scrap Trawler

Myr Retriever

How it works

1. Activate Ashnod's Altar by sacrificing Scrap Trawler, adding CC.
2. When Scrap Trawler dies, it triggers, returning Myr Retriever from your graveyard to your hand.
3. Cast Myr Retriever by paying 2.
4. Urtet's first ability triggers, creating a 1/1 Myr artifact creature token.
5. Activate Ashnod's Altar twice by sacrificing Myr Retriever and the Myr token, adding CCCC.
6. When Myr Retriever dies, it triggers, returning Scrap Trawler from your graveyard to your hand.
7. Cast Scrap Trawler by paying 3.
8. Repeat.
9. Once you have infinite colorless mana, you may forego sacrificing the Myr tokens.