Spoilers, so, you've been warned.

Well, I guessed right, Katarina was a fake. The one Raymond killed that is. Yay one of my theories was proven correct. lol

Ilya did get a facelift to be Raymond...but temporarily, hence the real Ilya running around, not Raymond-as-Ilya.

It ended with the apparent death of Neville (which was kinda funny IMO) and a bunch of clues leaning pretty damn heavily into the old "Raymond is really Katarina" theory. Which would be bizarre since the producers mocked it previously. Somehow Boone leaving made them re-consider it [possibly]? The clues that they left...the only other option is some rando who was friends of everyone involved who said "Sure why not I'll get a facelift to look like a man marked as a traitor. This is gonna be a gas."