In vidya terms, he'd be a Paladin. In tabletop terms, he'd just be a fighter in a class-lite system who has studied healing magic. "Paladin" implies more than just "fighty knight guy who can tank and cast white magic" in a tabletop context.>>49797333>>49798236>>49798326
Paladins are not clerics. Paladins are holy warriors with "divine" magical powers -- whether or not that divine magic is bestowed by a god in the same way a cleric's magic is bestowed by a god depends on the edition.
In 1e, 3e and 4e that was the default assumption; in 2e the default assumption was that they got their power from their stalwart allegiance to the cosmic forces of Good and Law; and now in 5e they get their powers from their oath, either in the name of a god or in the name of said cosmic forces.
It's not even confirmed that divine magic in the D&D sense even exists in the Dungeon Meshi setting -- all we know is that clerics can make holy water, which can then be used for exorcism purposes. We do, however, know that Farlyn studied at the same wizard school as Marcille. If I remember correctly, that wasn't the only place Marcille studied, so Farlyn didn't necessarily learn her white magic at a school that also taught dark arts, but that's still a possibility.