Myr Retriever + Ashnod's Altar + Mirrorworks

Myr Retriever

Ashnod's Altar

Mirrorworks

How it works

1. Cast Myr Retriever by paying 2.
2. When Myr Retriever enters, Mirrorworks triggers.
3. Holding priority, activate Ashnod's Altar by sacrificing Myr Retriever, adding CC
4. When Myr Retriever dies, it triggers, returning an artifact card from your graveyard to your hand.
5. Resolve the Mirrorworks trigger, causing you to pay 2 to create a token copy of Myr Retriever.
6. Activate Ashnod's Altar by sacrificing the Myr Retriever token, adding CC.
7. When the Myr Retriever token dies, it triggers, returning the nontoken Myr Retriever from your graveyard to your hand.
8. Repeat.