Well here are the updated character profiles
Pyrrha's story is mostly the same, only Sophitia is noted to be disappeared rather than dead. Weird.
Leixia is a fan of Journey to the West. Subtle.
Viola just flat out doesn't have a profile. She has personal information, but nothing else. Which is weird, as her original profile was infuriatingly vague to the point where it barely said anything anyway.
...Oddly enough, Pat's profile outright says Sophitia was killed. So it's still in the air if they are going to retcon her death or not. Also, Pat's bio now says that he is immature, is basically imitating (and is blatantly failing to match up to) an idealized view of Sophitia, and is nowhere near the hero he claims to be (and secretly knows it). I don't recall his original profile being so scathing.
Xiba's profile probably got the biggest overall change. It now explicitly states that his parents are Xianghua and Kilik. Basically, Xianghua was separated from Kilik while pregnant with Xiba, and forced by her grandfather to give him up upon marriage, and thus Xiba doesn't know who either of his parents are. Oddly enough, Xiba was raised and taught Kilik's fighting style (which Xiba then mutated into the style we see in V) by his grandfather/Xianghua's father and Xianghua does visit him once a year despite this. (So basically, Xiba is at least aware of Xianghua, but he doesn't know that she is his mother)
Like Viola, Natsu's profile was scrappped and we now just have bio details.
...Also, I just noticed, Natsu's profile was scrapped, and Leixia and Xiba's rewritten profiles omit all mention of their quest to find Kilik and stuff. I wonder if their storyline is going to be completely rewritten?
ZWEI's profile is also rewritten. EIN is renamed Minion. It is mentioned that he was orphaned as a child but was taken in by Siegfried with open arms, who raised him to be a warrior. Siegfried was basically the first person to show ZWEI kindness and before that, ZWEI lived alone in the slums and basically had to fight to survive. His upbringing is also why he is kinda flippant about death and violence and has next to no social skills.
Siegfried's backstory was rewritten: he went after Soul Edge solely to prove that he could wield it, and didn't kill his father until after he had already claimed it. He did succeed in reviving his father though...as an empty mindless shade. It was this that sparked the start of Siegfried's attempts to resist and give up Soul Edge.
Nightmare's profile is basically very brief retelling of his story through IV, though again, references to specific events (such as being defeated by Xianghua, Raphael being responsible for Siegfried's freedom, or Zasalamel creating his current body) are omitted.
Voldo's plot is unchanged.
Cervante's profile pretty much confirms that he was Nightmare during Soul Edge. The biggest retcon is that after Cervante's death, Nightmare revived him as one of his minions, but he eventually split off on his own and attempted to reforge the female Soul Edge. He was unable to control it compared to Nightmare, however, so he gave it up willingly and took on his old sword (which his evil heart corrupted). He now seeks out the completed Soul Edge.
Ivy's story is mostly unchanged, though it confirms that her new soul was created for a golem that would wield Soul Caliber for her.
Astaroth's story is mostly unchanged.
Maxi's story is mostly unchanged, though it now notes that the years of battle are taking a toll on his physical and mental well being (for example, it hurts for him to walk)
Aeon's story is mostly unchanged, though it changes the order of him reclaiming his soul and him regaining his sense of self after falling into madness. IV and V implied that he regained his self after gaining his soul, while the new profile says he regained it suddenly in the dead of the night, and now seeks to reclaim his soul so he could retain that.
Mitsurugi's story is unchanged.
Raphael's story is mostly unchanged, but the bits post-III are rewritten to make him into The Atoner (abit a anti-heroic one): he no longer wants Soul Calibur to use to create his "perfect world", but rather he believes it will cure Amy and will do anything to save her, as it is his fault she was corrupted to begin with. Also, there is mention of Amy's skin turning mottled black.
Dampierre's story is basically where it was at in IV. He notices Hilde's passion to ave her country and pulls a Heel-Face Turn for her.
Kilik's story is unchanged, though he now knows that Soul Calibur is evil and both need to be forced into eternal balance with each other to be neutralized.
Hilde's story is unchanged.
Xianghua's story is mostly the same, though she and Kilik are explicitly stated to be lovers and are stated to be the biggest experts on Soul Edge stuff outside of Soul Edge wielders themselves. Also, after Kilik got his ass kicked by Zasalamel, Edge Master encouraged Xianghua to train both her body and spirit.
Sophitia's story is mostly the same, though it is mentioned that she went on the quest to destroy Soul Edge during II onwards of her own volition (not encouraged by the gods or Cassandra or the like. In fact, she can no longer hear the gods)
Yoshimitsu's story is mostly the same, though it mentioned he created the Manji Clan to both protect the weak and find and deal with Soul Edge shards.
Taki's story is unchanged.
Amy's story mentions that she started turning black as soon as she was first infected treating Raphel's wounds, and she is starting to lose herself to the malfestion. She seeks out Soul Edge because she believes it is calling to Raphael.
Talim's story is unchanged.
Setsuka's story is unchanged.
Yunseong's story is pretty much rewritten to make him less of a dumb. He didn't run away to find Soul Edge, he was explicitly sent. Likewise, he does catch on that Soul Edge is evil (though only after being told by Hwang; Seong Mina and Talim failed to get to him) and is now questing to destroy it.
Seong Mi-na's story is unchanged.
Rock's story is unchanged.
Cassandra's story is mostly unchanged, though it is mentioned that the evil presence in Raphael's castle is what broke her weapons originally, and she didn't know that Sophitia left again until she returned to have them repaired.
Zasalamel's story is mostly unchanged from what it was in III (but not IV), though it now mentions that he was banished from his tribe for trying to claim Soul Calibur for himself and didn't gain his reincarnation magic until afterwards. It also mentions that each time he reincarnates, he feels he is "sinking deeper into hell" and that physical and mental anguish is the world punishing him for defying nature.
Algol's story is mostly unchanged from IV.
Tira's story is mostly unchanged, but they elaborate on her backstory. Before the Evil Seed, she was basically an empty shell that existed only to kill, with a soul that is "empty", and afterwards she was basically a aimless drifter before being corrupted into Nightmare's servant.
Arthur's story is the same, though it is noted that his wife turned black the same way Amy did before she died.
Hwang's story is mostly unchanged. Also, he told his superiors that Soul Edge was evil, but they didn't believe him and sent him (and later Yunseong) after it anyway. Jerks.