He lost his hair and other features like nose and different eyes BC of the horcruxes and since it was spilt in 7 other pieces it's destroyed the features that require a soul. But hey, this makes sense too.
I'll always be a fan of Dramione. Seriously, the whole "inter-house unity" bit throughout the books and umm. you don't get a major character pairing between Slytherin and Gryffindor? Anyway, thought you'd like this.
I actually wouldn't mind if she killed Tris. It would actually be a really powerful moment if she killed Tris and she died because she was protecting something, showing that she's willing to die for her cause.