This is especially useful if you want to create a themed set say, a custom commander cycle, a series of tournament memories, or a collection of card alters you've created
Cast Yuna, Hope of Spira to cast enchantment creatures with a bonus and Summon: Bahamut to inflict widespread damage
unlike all other unique skills which either give temporary buffs/debuffs or do damage, Ramza's skills notably increase stats for the entire battle and to which enemies in battle rarely have a way to counter (namely break skills, which very few enemies will carry and use)
Similarly, if Lightning leaves the battlefield and later returns, you won't be able to play the cards that were exiled the first time it was on the battlefield since it's a new object
Its inclusion in the deck makes it worth grabbing as a potential alternative to Queens Castle