Similar to other RPGs the combat system, the abilities the player can use will have a certain affinity. Affinities can be stronger, weaker, or neutral against each other. There's the classic fire, water, grass. But there is also Rock, Wind, Lightning. And then there is Light and Dark. Light and Dark are abilities most enemies will have by default with other affinities depending on the type of enemy.  It's nothing so complex as say the type chart in Pokemon, but I feel having 3 affinity wheels is enough to keep fights engaging.