First, Ral needs to be on the battlefield
Maximus had previously appeared on the "Maximus, Relentless Pursuer" card
In this deck you will find a lot of great staples in this deck directly out of the box that you can then use towards building your own hyper-powerful Amber/Amethyst deck list, or any Amethyst deck for that matter
Id slip it into a deck with some ways to recoup your life, and potentially ways to reset it by bouncing it, such as Master Transmuter, or blinking it, such as Teleportation Circle
Terras ability to retrieve Summons could be a nod to her half-esper side since espers are the Summon entities in FF6
Clouds mind never fully recovers from the trauma, which is why the scene of Zack handing him the sword and Cloud unconsciously adopting Zacks identity, becomes one of the most important reveals in the entire game