My feelings about this are mostly good, but there are a few things I'm not particularly positive about (mainly some of the characters). I'll start with the positives first. The cast, while given very little time to work with, was pretty likable. I don't think it topped the first game's chemistry, but it was still a nice group to romp around with and do sidequests. Plus, knowing that this was going to end badly really made me attached to them. This also made the inevitable deaths and conclusion hit pretty hard. Second, I enjoyed the battle system quite a bit. While I think I prefer the original's battle system, it was still engaging system to play with. Plus, getting to control everyone helped create a more visceral attachment to the characters, which is a strength this battle system has over the original in my view. Third, the sidequests in this game were superb. They were a lot more character driven, both in terms of the side characters and the main characters. Plus, having side-characters show up in multiple sidequests really helps give the world a sense of cohesion and builds a bond to the side-characters. Last, the world exploration, while not quite as varied or grand as the main game, was a lot more efficient, mostly due to the limited field skill options. There's also nice QoL improvements like being able to see what collection points give.
Now for the negatives... First, the game's pacing felt kinda all over the place. You had moments where they were dumping a lot of information on you and a lot going on, but then you'd also have really slow a chill moments too. I honestly think I would've preferred it if they just assumed everyone had played the main game first. That way, time that was put into redundant information could've went into building the characters instead. Speaking of the characters, I really wish they had taken time to flesh some of them out. Minoth, Haze, and all of Team Hugo feel particularly underdeveloped. I like all of them and think they had potential to become really interesting characters, but the game never really found the time to explore them in-depth, though I will say I don't think Minoth's case isn't as bad as the rest of them. I don't think they're bad characters (static doesn't equal bad), but it feels like there's lost potential there. As for Lora, I think she, much like Team Hugo, is pretty likable and has a lot of potential, but I don't think the arc with her father was particularly effective, which makes her feel a little out of place as a protagonist. I think she gets about as much of an arc/development as Morag, but in contrast, Morag didn't get as much spotlight and also had Brighid's arc complementing her, which evens things out in Morag's case. However, I do like how they have her interact with Mik; it really does a nice job setting up Mik's motivations in the main game. I think Milton did a nice job fufilling a similar purpose for Mythra, for he was largely the catalyst for Pyra's creation.
Speaking of Mythra, I'll talk about them for a bit... Generally, I like quite a bit what they did with the two of them; they may as well be the main characters of the game. Mythra, while her agency is quite reduced her, is still quite interesting and has a nice character arc. Not only that, they also did a good job showing how Mythra got into the state she was in in the main game; I think they did a great job with her. Likewise, I like Addam quite a bit. They did a good job portraying him as a great person, but still as someone ultimately not capable of preventing this tragedy. His role in shaping Mythra, and his actions after Torna's demise really helps flesh him out I think.
As for the villains (Gort, Malos, and Amalthus), I largely think they were serviceable, but nothing great. Gort is a solid villain, particularly for Lora, but I don't think he left much of an impact. He works alright as a villain, but I don't think he's particularly great. Likewise, Malos and Amalthus lost a lot of their nuance from the main game due to their time crunch. I think Malos was especially hurt in this regard, as his character and background were some of my favorite parts about him in the main game. I still think Malos is a pretty good villain, as his voice actor (English) still does a great job with the action scenes. However, I think some of his subtle lies had to be cut due to the nature of this expansion.
Overall, I enjoyed this expansion quite a bit, and I think its a nice way to conclude Xenoblade 2. There's some things I don't particularly like, but I still enjoy it nonetheless and will likely return to it in the future.