It had nothing to do with Alice choosing Kate over him at all.. do you not get what happened or something he only killed Enigma to get Alice to realize she was better off without Kate and reminded her of all of the things Kate did to her and how she didn’t need anything like that in her life again that wasn’t him being selfish if he was being selfish he would’ve been doing that only for himself and not thinking abt Alice which wasn’t the case, he was doing that for Alice and was thinking of her because he loves her and didn’t want her to get hurt by Kate again considering all of the things that happened.