ultimate

Meteor

Cosmic devastation

magic (MA x Faith, mitigated by MDEF)

Job: Arcanist
MP cost: 45
Charge: 8 CT — the caster is out of the turn order until it lands
Power: 50
Range: 5 tiles
Area: diamond r3
Targets: anyone in the area
Accuracy: 100%
JP to learn: 800

Rolling it

Nothing is guaranteed. At the start of each battle a unit's primary job rolls every ability it knows, one at a time.

As your primary job: 10%
As a sub-job draw: 1% of the bucket

Roughly one unit in 150 skips the roll entirely and fields its whole catalogue. If a unit rolls nothing at all, it is granted its cheapest ability rather than being sent out empty-handed.