Scrap Trawler + Myr Retriever + Krark-Clan Ironworks + Stone Calendar

Scrap Trawler

Myr Retriever

Krark-Clan Ironworks

Stone Calendar

How it works

1. Activate Krark-Clan Ironworks by sacrificing Myr Retriever, adding CC.
2. When Myr Retriever dies, it triggers, returning Scrap Trawler from your graveyard to your hand.
3. Cast Scrap Trawler by paying its mana cost, which is reduced by Stone Calendar.
4. Activate Krark-Clan Ironworks by sacrificing Scrap Trawler, adding CC.
5. When Scrap Trawler dies, it triggers, returning Myr Retriever from your graveyard to your hand.
6. Cast Myr Retriever by paying its mana cost, which is reduced by Stone Calendar.
7. Repeat.