Yenna, Redtooth Regent + Airtight Alibi + Careful Cultivation + Thaumatog

Yenna, Redtooth Regent

Airtight Alibi

Careful Cultivation

Thaumatog

How it works

1. Activate Yenna by paying 2 and tapping it, creating a copy of Airtight Alibi attached to Yenna, and then untapping Yenna and causing you to scry 2.
2. When the Airtight Alibi token enters, it triggers. Holding priority, activate Yenna by tapping it, adding .
3. Resolve the Airtight Alibi trigger, untapping Yenna.
4. Activate Thaumatog by sacrificing the Airtight Alibi token.
5. Repeat.

This intricate loop turns Yenna, Redtooth Regent into an endless enchantment-copying engine by utilizing the untap trigger from Airtight Alibi whenever it enters the battlefield. Because Airtight Alibi is an Aura that successfully untaps Yenna upon entry, Yenna immediately becomes ready to tap again for another copy. To keep the cycle going and fuel Yenna's activation costs, Thaumatog steps in to sacrifice the newly created Airtight Alibi token, clearing the board for the next iteration. Meanwhile, Careful Cultivation sits in reserve, though its channel ability can be used to set up early mana, and the overall sequence conveniently generates infinite scrying alongside an infinitely large creature.