Since the effect for your opponent is not a requirement to play the card, there are times when you will get to play a character even if your opponent has nothing in their hand to send out
While Vivi's Persistence is in the graveyard, it can be returned to its controller's hand by paying two mana whenever their commander enters play or attacks
Instead, whenever there's a character on the Institute of Technology, you get one free lore every turn
For example, if you control The Ozolith ("Whenever a creature you control leaves the battlefield, if it had counters on it, put those counters on The Ozolith.") when Zack Fair's last ability resolves, you'll put the appropriate number of each kind of counter onto both The Ozolith and the target creature
But, it's also worth noting that prices change all the time, so some cards may change in value closer to release
This theme works on three levels: Payoffs (i.e., Judge Magister Gabranth, Al Bhed Salvagers) Sacrifice outlets (i.e., Phantom Train, Namazu Trader, Ahriman) Fodder (Hecteyes, job select equipment, Rufus Shinras poor disposable dog) A good WB deck has a healthy mix of all three, plus lots of strong removal spells like White Auracite and Sephiroth's Intervention