Morophon, the Boundless + Dream Stalker + Leyline of Mutation

Morophon, the Boundless

Dream Stalker

Leyline of Mutation

How it works

1. Cast Dream Stalker by paying 0.
2. When Dream Stalker enters, it triggers, returning itself from the battlefield to your hand.
3. Repeat.

This loop hinges on combining Leyline of Mutation's alternative cost with Morophon, the Boundless to bypass the mana restriction entirely. With Morophon naming the creature type of Dream Stalker, its passive cost-reduction exactly matches the five-color requirement of Leyline of Mutation, allowing you to cast Dream Stalker for free. When Dream Stalker enters the battlefield, its mandatory triggered ability forces it to return itself to your hand, perfectly setting up the loop to endlessly repeat for infinite storm count and creature triggers.