This gives you a little extra value for the initial spell, and Rinoa specifically also has an ability that works better the more creatures you have
Its a great aesthetic, and its clearly proving to be very popular among Final Fantasy/MTG fans, given the prevalence of this card type on this list
On the sapphire side, cards such as Winnie the Pooh, Having a Think will help you to build up your inkwell quickly, giving you more resources to play cards on your turn
Combustion Technique Zuko, Conflicted Azula, Cunning Usurper Aang, at the Crossroads / Aang, Destined Savior Katara, the Fearless Dai Li Agents Avatar: The Last Airbender Book 3 Here's where the conflict becomes decisive
Creature - Human Cleric Color tag templates(None) Amoeboid Changeling Changeling (This card is every creature type.) : Target creature gains all creature types until end of turn
These cards see a lot of play outside of these decks, too, roughly to the same proportions as their costs