Kirol, Attentive First-Year + Conjurer's Closet + Midnight Guard

Kirol, Attentive First-Year

Conjurer's Closet

Midnight Guard

How it works

1. At the beginning of your end step, Conjurer's Closet triggers.
2. Holding priority, activate Kirol by tapping it and Midnight Guard. copying Conjurer's Closet's trigger, targeting Kirol.
3. Resolve the copy of Conjurer's Closet's trigger, blinking Kirol.
4. When Kirol enters, Midnight Guard triggers, untapping Midnight Guard.
5. Repeat from step 2.

By starting the chain with the end-step trigger of Conjurer's Closet, you can leverage Kirol, Attentive First-Year's ability to copy that very trigger by tapping Kirol and Midnight Guard as costs. Because the copied trigger resolves first and blinks Kirol, its entrance back onto the battlefield triggers Midnight Guard to untap itself, neatly resetting the pair to do it all over again. This recursive loop produces an endless stream of creature enters-the-battlefield and leaves-the-battlefield events, perfectly exploiting the interaction between continuous triggers and activated copying.