Running out of MP isn't an issue in short excursions, but as you settle into longer combat sections, it'll creep up on you.
The Hero Passive ability for the Mage is Magic Recovery, which recovers a little MP every time an enemy is stunned or defeated in overworld combat.
While you can stun or defeat enemies this way as any class, the MP restoration works only for characters with the Mage archetype equipped.
By the time you're running out of MP, you should have enough MAG to unlock the Mage class unless you already spent it on other classes and abilities.
Collection
[
|
...
]