Quick rundown of the heroes (at least of the games I've played, which are DQ 1-8) without getting into the actual mechanics. Spoilered in case you don't really care about the summary of each hero's abilities.

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In DQ1 the hero was kind of a magic knight type. Could use any weapon or armor in the game, but... he was also the ONLY playable character in the game, so that doesn't really have much weight. DQ1 was also pretty much the first JRPG. He was also good with magic, his spell list including healing, direct damage, and status effects (sleep and 'stopspell,' which is basically Silence in D&D terms.)

In DQ2 there were three heroes, who were the direct descendants of the hero from DQ1. The 'main' hero, the prince of Midenhall (Lorasia in the GBC port/remake, though only that version - later ones returned to using the name Midenhall) was the one you played first and the one you named. He was good with weapons and armor and had REALLY good physical stats, but he couldn't use magic at all.
- The second hero in DQ2, the prince of Cannock, was a hybrid character, like the hero from the first game. He could use some weapons and armor and could use some magic, but he wasn't really very good at either of them (at least in the original version, remakes would expand his equipment options quite a bit and make his magic significantly stronger.)
- The third hero in DQ2 was the Princess of Moonbrooke, who was pretty much your typical mage. Poor equipment options, but she could use some very powerful magic.

DQ3 and 4 went back to the hero being a hybrid character (though leaning towards the more physical side, able to use almost all weapons and armor,) and generally the best character in the game. The heroes from these games are very similar, having access to powerful healing spells (DQ4 introduced the HealUsAll spell, which restores the entire party to maximum HP, though it's very costly,) as well as introducing what would become a signature of the 'hero' class: lightning spells. From here forward, lightning-type damage is generally considered holy and/or something only able to be wielded by The Legendary Hero in the series.

DQ5's main character is in fact NOT The Legendary Hero, but rather a cleric-type character with access to healing and wind-elemental spells (which are a mainstay of the cleric or priest-type classes in the series.) The Legendary Hero is playable later in the game, and in most respects is basically the same as the DQ3 and 4 incarnations.

DQ6 and 7 take a major detour from the 'class' based advancement that previous entries had, and now have 'jobs' for characters instead, which are kind of like a template applied to a character's base stats. Any character can take up any job (any job they qualify for, at least - there are some advanced and hybrid jobs that require mastering 'base' jobs first. Like, the Sage job requires mastering Mage and Priest first, etc.) With enough grinding ANY character can take up the 'Hero' job, which grants access to a lot of the same abilities the Legendary Heroes from 3-5 had, but the main characters of these games have the special quality of being allowed to access it with only 1/4 the normal requirements met.

DQ8 takes another detour from BOTH the advancement systems of the previous games and instead has you allocate skill points upon gaining a level, in one of five skill categories, with each character having their own set of skills (mostly - the hero and Angelo, the priest-type companion, both have access to the 'swords' skill tree. While their Sword skills are not identical, they ARE very similar, with both characters gaining access to most of the same skills if you choose to invest your skill points in swords for both of them.) In addition, you gain abilities and spells as you level up that aren't affected by where you allocate your skill points. The hero's 'level' skills are largely the same abilities the heroes from 3-5 had, and that the 'hero' job in 6 and 7 granted. Healing, protection, support, etc.


So a summary of the signature 'hero' abilities are:
- Good with weapons and armor, able to use most if not all of the ones available in the game, often including a unique set of weapons that only The Legendary Hero can use.
- Healing and/or protective spells, which the hero tends to be VERY good with.
- Lightning elemental direct damage spells, with lightning damage generally being considered 'holy' in the series.

Conclusion: Paladin fits almost perfectly, both mechanically and thematically. The hero is usually 'The Chosen One' or has some divine lineage. Maybe swap out the paladin's mount with the ability to make smites at range or against multiple enemies in a single round.