Tawnos, Solemn Survivor + Ashnod's Altar + Corridor Monitor

Tawnos, Solemn Survivor

Ashnod's Altar

Corridor Monitor

How it works

1. Activate Tawnos's second ability by paying 1, tapping it and sacrificing two artifact tokens, exiling Corridor Monitor from your graveyard and creating a token copy of it that is an artifact in addition to its other types.
2. When the Corridor Monitor token enters, it triggers, untapping Tawnos.
3. Activate Tawnos's first ability by paying 2 and tapping it, creating a copy of the Corridor Monitor token and causing you to mill two cards.
4. When the Corridor Monitor token enters, it triggers, untapping Tawnos.
5. Activate Ashnod's Altar by sacrificing a Corridor Monitor token, adding CC.
6. Repeat from step 3.