@Mu11berry's in-depth playthrough and commentary of AV2 has led me to do some thinking on my favorite and first Aveyond game, and I've come to a realization on why it stands apart from the other AV games (for me, anyway).
Aveyond 2 is ultimately a story about building people up so they can help others heal. All of the games have this element of character development, but in AV2 it's literally the entire plot. In AP the 'collection quest' is building a weapon, in AV1 it's defeating the daevas, in AV3 it...jumps around a bit, but it's still focused on defeating Gyendal more than anything, and AV4 doesn't have one I think? But SotM is so different thematically from the others I'll just leave it aside. But in AV2, it's about restoring Iya's spirit, making the protagonist's character development and growing strength into something literal, rather than being about destroying or defeating a villain.
And as far as the final battle goes, all the others are fairly straightforward - defeat the evil villain with the help of your party so good prevails. Not that I have any problem with this plot - it's a classic for a reason, after all - but it makes me appreciate AV2's final battle all the more. First you have to defeat the Snow Queen, the antagonist of the game...but you don't really defeat her, you redeem her. The Snow Queen is Ishtar, the nymph of compassion - which is exactly what Iya showed when she gave Ishtar the love blessing at the end. Ishtar took Iya's spirit, so now Iya has to give Ishtar her spirit before she can receive the final blessing and go home. See the parallels?? Giving, not taking or defeating, is the answer. And even Heptitus, the real 'big bad', isn't a standard villain either. As the nymph of wickedness, Iya needed her blessing to be whole again, just as much as she needed Ishtar's blessing. And as the nymph of wickedness, she's really expected to do these kind of things anyway And at the end, rather than punishing her children, the Goddess shows forgiveness and gives them an additional chance to redeem themselves.
The characters in the party reflect this theme as well. Ean is the main character and party leader, but his main goal is to help Iya with her journey and to unite the kingdoms behind her. This struck me as odd to have a side-character as the protagonist, but now I realize it fits with the theme of supporting and building others up. Nicolas' story is almost a microcosm of the plot as a whole, since he grows so much as a person once he's exposed to the world. He wasn't really a bad guy - spoiled and selfish and naive yes, but not truly evil - but like Ean and Iya, his journey (and Ava, bless her) turned him into the best version of himself. It wasn't about breaking the haughty, it was about turning him into a better person.
Aaaaaand I'll stop ranting now