Morophon, the Boundless + Spider-Man 2099, Miguel O'Hara + Leyline of Mutation

Morophon, the Boundless

Spider-Man 2099, Miguel O'Hara

Leyline of Mutation

How it works

1. Cast Spider-Man 2099 by paying 0.
2. When Spider-Man 2099 enters, it triggers, returning itself from the battlefield to your hand.
3. Repeat.

This loop relies on Leyline of Mutation to bypass the traditional mana costs of your spells by letting you pay {W}{U}{B}{R}{G} instead, a steep requirement that Morophon, the Boundless completely eliminates by choosing a shared creature type to reduce that exact colored cost to zero. With the spells thus free to cast, you simply deploy Spider-Man 2099, whose entry trigger immediately forces it right back to your hand. Because Leyline of Mutation makes casting it cost nothing and Morophon, the Boundless ensures it hits the battlefield for free, you can endlessly repeat this sequence to generate infinite enters-the-battlefield and leaves-the-battlefield triggers alongside an arbitrarily high storm count.