Pirated Copy + Felidar Guardian

Prerequisites

You have enough mana to cast Pirated Copy.

Steps

1. Cast Pirated Copy by paying its mana cost, choosing to have it enter the battlefield as a copy of Felidar Guardian
2. When Pirated Copy enters the battlefield, it triggers, blinking Felidar Guardian.
3. When Felidar Guardian enters the battlefield, it triggers, blinking Pirated Copy. Choose to have Pirated Copy enter the battlefield as a copy of Felidar Guardian.
4. Repeat from step 2.