Don Corneo, because they manage to really drive home that despite his weirdness and campiness, he's actually an evil, disgusting person who is running a trafficking and rape outfit. Which he always was, but in the original it always felt like he was pure comic relief; here he's comic relief, but it's shaded with his actual depravity.

Aerith like others have said, she's not changed much but the time they give to expanding her, her playfulness, her willingness and determination to get things done even if they're dangerous, they're all just superb.

Barret goes from great to best boy, both because of his expanded screentime and because his VA earns every cent.

And Jessie was always Best Girl but now she's just... I don't have smilies to encapsulate how much I love Best Girl.