Every Final Fantasy game is unique and disconnected from the rest, but tends to share similar themes, enemies, and allies
Celes was considered for 6 since the deck is focused around the World of Ruin and the second half of that game, while Yuna was considered for 10 as a fan-favorite
Purestrains prepare the battlefield and Broodlords ensure they can keep doing that, until eventually you have Patriarchs to come and turn their enemy's strength against each other
Since Mirri, Weatherlight Duelist has first strike, you dont have to worry as much about attacking with it to benefit from its abilities
Because it costs only a single black mana, it comes down early and keeps paying dividends
The beautiful, picturesque artwork pulls a lot of inspiration from the film and makes for a great collector piece