So, there's a lot for me to talk about with these updates, but I'll try and keep my thoughts brief:
1) I like that we're getting backstory on Eraqus' absolutist anti-darkness ideology. And also, no, there's no way his grandfather is Brain like some people are saying. Brain and the Union X people existed hundreds, maybe even thousands of years ago. We've never gotten a concrete number, but all references to the Age of Fairy Tales are always couched in phrases like "ancient," "long ago", and "antiquity." Going back three generations does not line up with that kind of massive timejump. Whoever Eraqus' grandfather was, it'll be a new character.
2) I'm conflicted with how they're treating darkness in this story. I mean, it's Kingdom Hearts, and darkness has always been this quasi-metaphysical abstract yet also concrete emotional/cosmic force, but I feel like this story is starting to push the bounds even further. I mean, I see the connections they're trying to make to the Union X developments, but I have some reservations about where they're going with this. Mainly, I'm not sure the idea they're setting up with how darkness and the evil in people's hearts interact is a good message. In the past, darkness could manifest itself as strange powers or as Heartless, which is fine enough, but there was always an underlying understanding that said darkness originated from deep character flaws that would eventually be the undoing of the person who succumbed to their own darkness. The Disney villains in KH1 and 2, for example, all gained control of the Heartless because of darkness in their hearts that germinated from emotions like greed, envy, rage, etc. And they're sort of following that pattern here with the Queen of Hearts, but I don't think I jive with this idea that darkness is some kind of alien presence that entered human hearts and now just sort of co-evolved with them. That implies that everyone in Age of Fairy Tales was always pure of heart, which is demonstrably not the case. Furthermore, it sends (I think) a very questionable message to kids that evil is not something that grows out of your own failings, actions, or insecurities, but that it's something external to you, that you don't have complete control of your own actions regarding it. Maybe I'm giving it too much weight, but that kind of message just struck me as particularly off-putting.
3) I'm getting kind of ambivalent about how they're handling Xehanort in this game. I can see where they're going with his development, but it's very hard to take his journey seriously when one minute he's talking in these super-broody monologues about darkness and the next he and his friends are having conversations with Tweedledum and Tweedledee about walruses and carpenters. Nomura needs to work the story around Xehanort's character a bit better. Xehanort is NOT Sora. Going on adventures like this works for someone like Sora because Sora's childlike, carefree, lighthearted, and inquisitive personality meshes really well with the Disney aesthetic and characters. But Xehanort is a more dour, somber, contemplative, and mature character, and they need storylines and environments that help foster his development regarding his personality. It's just too jarring for the main character to be constantly talking about darkness while also having these abundant silly moments with the other characters. They had this same problem in Birth by Sleep as well—you can't just toss in these soliloquies about how people become corrupted and how characters struggle with internal moral conflicts, while in the next breath showing those same characters balling around in Disney Town and riding go-karts. It just doesn't work. Terra's storyline was an especially bad example of this. KH1, CoM, and to a lesser extent KH2 all managed this balance a lot better than subsequent games, CoM most of all imo. At some point, Nomura started treating each Disney world as an opportunity for simplistic hamfisted moral lessons. KH1 and CoM were better at just incorporating the worlds into the broader development of the character and their journey, showing us rather than telling us what they were supposed to learn from their encounters and experiences, and their journeys were more relatable, whereas Terra's and now Xehanort's are far too muddy and abstract. If we're going to go the route of showing a character build up from a curious youth into a disillusioned villain, then you have to do things to build the bridge between Point A and Point B that resonate on an emotional level with normal people. You can keep the light-dark cosmology for the sake of worldbuilding, but you need to put Xehanort through real, actual, relatable hardships instead of focusing on the mechanics of how evil works. And they probably will, to be fair. We know that Xehanort's friends die at some point, which is a good, mature example of what to do right in building Xehanort's character, but I hope there will be a buildup of smaller, gradually increasing losses, hardships, and frustrations leading up to that, because if they just throw that at him as the singular reason for why he turns evil and replace the rest of his development with all these other flights of pseudo-metaphysical ponderings, it's going to feel very blunt and unrelatable, like Anakin's turn to the dark side in the Star Wars prequels.
At the end of the day, I know it's still Kingdom Hearts and I shouldn't expect them to get too serious, but the earlier games always had this sense of groundedness to their characters—the light/darkness jargon needs to get toned down and replaced with words that real people would actually use to describe what they're feeling.