The biggest weakness of the deck is its early game
The aforementioned Starter Kit is a great way to onboard learning how to play the game, and you can keep it within the Final Fantasy theming if you and one other player use just that
The answer is: dont play life-gain spells
From there, you can win the game as long as your deck containedDread Return, three copies of Narcomoeba to sacrifice to Dread Return, and Thassas Oracle to reanimate with Dread Return
This is the ideal first turn body, second turn attack with free pump like Mutagenic Growth or Invigorate that helps to win, followed on that turn by dropping this guy
Many of the series luminary visual artists got to pick which characters they illustrated, with new Terra and Kefka art from Amano and an extensive and impressive Sephiroth piece from Tetsuya Nomura