Kaaya was always awesome and still is. I'd be surprised if they didn't give her good reasons for doing what she's doing.
Fatina was always great for shallow reasons, but she's actually been pretty likable since she hung out with Jil and became a little more than a tsuntsun Neeba fangirl. Also, Fatina haet secretive manipulative people, so she's probably not a huge Neeba fangirl at this point. Notice how she didn't follow him up the tower when offered. They've been hinting at Jil X Fatina ever since episode 9, so its not like its completely out of the blue.
It'll probably end with a Kaaya end, though. More drama surrounding her, more parallels to Ki X Gil, etc.