There’s still a lot we don’t know about Square-Enix’s upcoming smartphone RPG, Mevius Final Fantasy. It’s supposed to hit mobile (in Japan) this spring, and apparently elements and “ability cards” will play into its battle system quite heavily.
When attacking enemies in Mevius Final Fantasy, you’ll gain “Elements,” which are then used to activate abilities. Abilities have their own types and number of required elements to use. Additionally, there are Ability Cards you can use when requirements are met.