Mendicant Core, Guidelight + Krark-Clan Ironworks + Myr Retriever

Mendicant Core, Guidelight

Krark-Clan Ironworks

Myr Retriever

How it works

1. Cast Myr Retriever by paying 2.
2. Mendicant Core triggers, causing you to pay 1 to copy the Myr Retriever spell, creating a token copy of it.
3. Activate Krark-Clan Ironworks by sacrificing the nontoken Myr Retriever, adding CC.
4. When Myr Retriever dies, it triggers, returning another artifact from your graveyard to your hand.
5. Activate Krark-Clan Ironworks by sacrificing the token Myr Retriever, adding CC.
6. When the token Myr Retriever dies, it triggers, returning the nontoken Myr Retriever from your graveyard to your hand.
7. Repeat.