Pearl-Ear, Imperial Advisor + Cloudstone Curio + Faceless One + Ugin's Mastery

Pearl-Ear, Imperial Advisor

Cloudstone Curio

Faceless One

Ugin's Mastery

How it works

1. Cast Faceless One by paying 0 due to Pearl-Ear.
2. When Faceless One enters the battlefield, Cloudstone Curio triggers, returning Ugin's Mastery from the battlefield to your hand.
3. Cast Ugin's Mastery by paying 0 due to Pearl-Ear.
4. When Ugin's Mastery enters the battlefield, Cloudstone Curio triggers, returning Faceless One from the battlefield to your hand.
5. Repeat.

This clever loop achieves infinite casts and triggers by exploiting the unique card types of your permanents alongside cost reduction. Because Pearl-Ear, Imperial Advisor gives your enchantment spells affinity for Auras, your legendary creature and enchantment can both be cast for free when an appropriate permanent is controlled. When Faceless One enters the battlefield, Cloudstone Curio triggers to bounce Ugin's Mastery back to your hand, and when Ugin's Mastery is subsequently recast for free, Cloudstone Curio bounces Faceless One right back. Though the manifest and attack triggers from Ugin's Mastery aren't even necessary for the loop to function, the endless repetition effortlessly generates an infinite storm count and countless enters-the-battlefield triggers.