Harald Unites the Elves + Moritte of the Frost + Leyline of Singularity

Harald Unites the Elves

Moritte of the Frost

Leyline of Singularity

How it works

1. Cast Harald Unties the Elves by paying 2, causing it to enter the battlefield with a lore counter on it.
2. Harald Unites the Elves' first chapter ability triggers, causing you to mill three cards, and return Moritte from your graveyard to the battlefield as a copy of Harald Unites the Elves with one lore counter on it.
3. Put Moritte of the Frost into your graveyard due to the legend rule.
4. Moritte of the Frost's first chapter ability triggers, causing you to mill three cards, and return Moritte from your graveyard to the battlefield as a copy of Harald Unites the Elves with one lore counter on it.
5. Repeat from step 3.

This mesmerizing loop relies on Leyline of Singularity's static ability to turn all nonland permanents into legendaries, laying the groundwork for the legend rule to do the heavy lifting. When you cast Harald Unites the Elves, its first chapter lets you pull a matching card from your graveyard, specifically targeting Moritte of the Frost. Because Moritte enters as a copy of Harald Unites the Elves, Leyline of Singularity immediately forces you to send the copy to the graveyard due to uniqueness, triggering its own first chapter on the way out to perpetually recur itself and achieve infinite self-mill.