Elemental Affinity
A spell which deals lightning damage to a single enemy, it's learned by Black Mages at level 21.
What is Thunder?
The Bomb monster family's resistances seem to change in every Final Fantasy game, but in Vana'diel, they typically resist all magical elements except this one.
What is fire?
This day, between Lightningsday and Darksday, has a chance to boost the power and accuracy of spells like Banish and weaken spells like Drain, or is guaranteed to do so if you're wearing a Korin Obi.
What is Lightsday?
Casting this spell can help you and your party resist damage of the named element, and further potentially protect you from stifling status effects like Attack Down or Strength Down.
What is Barwatera?