Requires

Tawnos, Solemn Survivor must be on the battlefield. Retreat to Coralhelm must be on the battlefield. Caged Sun must be on the battlefield. Vault of Whispers must be in the graveyard. Tawnos does not have summoning sickness. "Black" chosen with Caged Sun. You control at least two artifact tokens. Mana needed:

Steps

1. Activate Tawnos' second ability by paying , tapping it, sacrificing two artifact tokens and exiling Vault of Whispers from your graveyard, causing you to create a token of Vault of Whispers.
2. When the Vault of Whispers token enters the battlefield, Retreat to Coralhelm triggers, untapping Tawnos.
3. Activate the Vault of Whispers token by tapping it, adding .
4. Caged Sun triggers, adding .
5. Activate Tawnos' first ability by paying and tapping it, creating a copy of the Vault of Whispers token and causing you to mill two cards.
6. Repeat from step 2.

Results