Thinking about Yuffie, I can't help but feel how great her characterisation has been here. It was almost non-existant in the OG. In the OG, you could feel that she was a kid and that was basically all there was to it. In Remake, you can also feel that she's very young, but there's more to it.
Here we can see at the start of the game that she not only wants Shinra down, but also Midgar. By the middle of the game, you can see that she's more hesitant because she realises that there are good guys there. By the end of the game, she's confronting the fact that Shinra is ruthless and can be quite evil if it matches its own needs. She really grows and become more empathic, and shows that she's able to care for people, after all. Sonon, on the other hand, has a grudge against Shinra and just like them is able to be quite evil if necessary I feel. He doesn't really care about Midgar being destroyed, even though he's been there for some time. They clearly used Sonon to showcase Yuffie's change, it was well done.
I wonder what it is about that mutant thing though. This... doesn't seem to be a throwaway line or something? Is it something new?