Kat's exbf seems like a normal well adjusted guy. Has a job outside of the house, has videos with friends, likes to go outside, has an interest in cars, likes music, does hair tricks. All in all, can't really see any mental illness from the very little we've seen of him.
The thing that is so weird to me is that Phil is boring as fuck. There is no spontaneity in his life, Saturday is Target day, Seattle/Zoo/Arcade is only for birthdays, other than that it's wake up at 11am, stream 5 hours, "dinner', stream 2 hours, netflix/gin until 4am and repeat.
Why would you go from an incredibly normal and social guy to one of the most boring and least adjusted guys with the worst reputation on Twitch. Girls get really bored easily, if you've never been nagged about "I'm boooorrrreeeed" by a girl, you're either really exciting or you've never had a girlfriend. When girls get bored, they cheat. Watch out for that saga soon.