My personal opinion is the following: they didn't want their "Original" characters(Halsin, Astarion and Shadowheart are different mixes of Viconia and Sebille wannabes) to be outshined or percieved as "weak", so, instead of making this a torch passing ceremony, they changed lore and events accordingly so that it comes as the torchbearers being beaten to a pulp and the torches taken by the new ones... the old evil characters are used as punching bags and purposefully character assassinated to elevate their originals and make people who don't know them, either hate them or be indifferent. It's a really disheartening treatment, and even tho i don't like when this sort of thing is done, it kinda does make me wish they get treated with their own medicine in case a next "BG" comes out, cause maybe at that point they might understand what other people meant(I have managed to convince two of my friends to understand what i mean and admit those characters aren't even the same... but i also have failed with others cause no matter how much context i provide, they just don't care). I called Durge fanfiction cause... there can't be Bhaalspawn around since Bhaal is not a god anymore, and giving his own powers to others(weakening himself) is not just out of character for how crafty Bhaal actually was, it is also extremely dumb cause it contradicts quasi-god lore.
Honestly, I don't think a bland image like Halsin could outshine anyone, no matter what Larian does with old characters, even though they PR him and shove him in the player's face as much as they can. Maybe they're trying to make him brighter than Jaheira, "Look at what a druid we have, strong like Minsc and a druid like Jaheira". He manages perfectly well to only provoke anger with his brash behavior and all the threesomes, thus cheapening Orin's kidnapping quest (which should, in theory, be perceived as a misfortune, and, the player, nervous and worried about their companion, should strive to get him/her out as soon as possible, becomes a grace: "Oh, my dear enemy, thank you, now I won't see him in my camp again until the end of Act 3!" and Orin's quest is postponed to the very end of the game). Also, I can't help but note that Astarion, unlike Viconia, is literally made a toy for a "mass audience" here, while at first a player in their headcanon might think it would be difficult to gain his trust, when you later find out all the options for his romantic line, it's sad. You can even bring Gandrel into the camp and still get a romance with Astarion at a party, it cheapens the very idea of gaining trust and establishing a close relationship with an embittered and distrustful character. Viconia, as I recall, was pretty good at ironizing and teasing the player character when they did stupid things from her point of view, not just the companions. I was interested in revealing her more fully, and I created a male Tav in the second playthrough of BG2 specifically to romance her. And it wasn't an easy thing to do. My character, I thought, behaved in a very caring way towards her, but was honored by criticism that he was "sucking up". It was interesting, I had to replay it, try different things, explore the character - yes, it's an interesting and complex novel. I consider Astarion an unusual and original character, unlike anyone else, including in BG2, but I can't help but admit that I have a subjective attitude towards him, I stay in this game just for him, I just think that for this character (especially if they left the original idea of Stephen Rooney, didn't make him "less evil" and stuff) there is no need to deliberately spoil old characters. Minthara could be compared to Viconia, but that wouldn't really be fair to Minthara - Viconia had a sea of text and lines, but poor Minthara has how much? I mean, I understand what you mean, I just wanted to say that Larian and their own evil characters are clearly treated without much love - Astarion becomes a symbol of "needing to be fixed and redeemed" and pays dearly for his popularity with the pain and humiliation of his most popular "good" ending, and Minthara was given the least attention. Viconia in BG2 could have been attached much more easily - an evil character had the motivation to save her because she was a drow, or out of hatred for the Inquisitors, a good one also had the excellent motivation to save someone from being burned alive. And could also dislike the Inquisition, but to want to kill Tiefling children, squirrels and cute bears - no motivation, either "evil for evil's sake" or metagame and do it purely for Minthara's sake.
BG's lore has been distorted as much as it can be, that's a fact. For the sake of promoting their characters or their "moral lessons", or on the principle of "that's fine, we won't try too hard here". But for some reason it's the evil characters that are used as punching bags, and it's them that are purposefully killed. Minsc made some kind of "source of wisdom" - he gives characteristics to all companions, naturally, on the principle of "good and asses". I can't say that Larian spoiled him somehow, I don't know, but for some reason in BG2 he was funny, but here he is so annoying by the end of the game that I want to say to him at the party: "Get away from this little guy (the thief, whom Minsc first cheerfully held upside down on the roof, and then brought to the party), take your good, shove it up your ass and... Next time I'll be a monster, just so my eyes don't see you or Jaheira." They beat to a pulp the very spirit of RPG, which was in BG1 and 2 - realistic world, where you can do anything, make any decision, the consequences can like or dislike, but they are realistic, companions are independent and autonomous, they tell you off sometimes so that no BG3 with their "crown on the head" and did not dream, the player is not licked from head to toe, but not trying to "teach lessons".
About Bhaal - thanks for the information, I didn't think of that at first, but it's really true.
I get the blah blah immortality "bad", as it can be a curse... it'd be interesting if Jaheira had that problem cause of Khalid's death being the first step towards aging really slowly and losing yet another partner during those 124 years... but that's the problem, she doesn't experience it in the first place.
For myself, that's the rationale behind Jaheira's reluctance to use this ritual on herself, though really, she doesn't express it herself. Karlach, who could die at any moment and is clearly not concerned with this motivation, looks like a complete fool admiring Jaheira's speech instead of latching onto that hope and demanding the ritual be performed on her.
Also, immortality becomes a blessing if those you love share it with you, cause you can express that love for the rest of eternity.
Beautiful words. That's how one should present a "dark romance" (and not only a "dark" romance, the options for immortality can be different) in a game. Larian, in my opinion, and here again "moral", only "evil" and "bad" character can want immortality.