Cast Sakashima of a Thousand Faces either from your hand or from the command zone by paying 3 plus commander tax if applicable. Choose to have it enter as a copy of Anticausal Vestige.
When Sakashima of a Thousand Faces enters, Cloudstone Curio triggers, returning Anticausal Vestige from the battlefield to your hand.
When Anticausal Vestige leaves the battlefield, it triggers, causing you to draw a card and and put Anticausal Vestige from your hand onto the battlefield.
When Anticausal Vestige enters, Cloudstone Curio triggers, returning Sakashima of a Thousand Faces from the battlefield to your hand.
When Sakashima of a Thousand Faces leaves the battlefield, it triggers, causing you to draw a card and put Sakashima of a Thousand Faces from your hand onto the battlefield as a copy of Anticausal Vestige.
Repeat from step 2.
This clever loop relies on the interaction between a unique creature and its clone to endlessly bounce and re-enter the battlefield. By casting Sakashima of a Thousand Faces as a copy of Anticausal Vestige, you set up a perpetual motion machine fueled by Cloudstone Curio's bounce trigger. Every time Anticausal Vestige leaves the battlefield, its delayed trigger draws you a card and lets you cheat out a permanent, while Cloudstone Curio effortlessly returns your other piece back to your hand to restart the cycle. Thanks to Sakashima of a Thousand Faces's text ignoring the legend rule and preserving its own identity, you can swap roles back and forth indefinitely to draw your entire deck and trigger countless enters-the-battlefield effects.