Alkali - SLE
Kai'sa - LSI??? ISTx probably
(I'm getting the impression that she doesn't really have a "personality" like the rest of the members. Maybe that's why she's an afterthought...)
Ahri - SEI
Evelyn - ESI

Seraphine - IEI from the More video

Anyways, my interpretation is very surface level and I'm just going off of the vibes of the people I've known in the past. Some of the types are different from the characterizations provided in the game. What do you guys think?