Adarkar Valkyrie + Intruder Alarm + Mirror Image

Adarkar Valkyrie

Intruder Alarm

Mirror Image

How it works

1. Activate Adarkar Valkyrie by tapping it, targeting any legendary creature you control.
2. Cast Mirror Image by paying 2, choosing to have it enter the battlefield as a copy of the legendary creature targeted in step 1.
3. Put the legendary creature into your graveyard due to the legend rule.
4. Adarkar Valkyrie and Intruder Alarm trigger.
5. Resolve the Intruder Alarm trigger, untapping all creatures.
6. Holding priority, activate Adarkar Valkyrie by tapping it, targeting Mirror Image.
7. Resolve the Adarkar Valkyrie trigger from step 4, returning the legendary creature to the battlefield from your graveyard.
8. Put Mirror Image into your graveyard due to the legend rule.
9. Adarkar Valkyrie and Intruder Alarm trigger.
10. Resolve the Intruder Alarm trigger, untapping all creatures.
11. Holding priority, activate Adarkar Valkyrie by tapping it, targeting the legendary creature.
12. Resolve the Adarkar Valkyrie trigger from step 9, returning Mirror Image to the battlefield from your graveyard as a copy of the legendary creature.
13. Repeat from step 3.

This clever loop turns the legend rule into an engine, using Adarkar Valkyrie to continuously resurrect whichever legendary creature you choose while leveraging Mirror Image as a flexible, self-sacrificing clone to keep the cycle going. Every time one of these copies succumbs to the state-based legend rule, Intruder Alarm catches the resulting entry and untaps all creatures—including your Valkyrie—so she can immediately tap again to catch the next falling clone. Because the Alarm untaps your board on every single creature entrance, any mana-producing creatures you happen to control will also go infinite along the way.