Okay, seriously now. TeamBlonde is not over; definitely. I mentioned it before but if Sungji ends ups being unrelated to Sumin/Seju this story could not work... Sungji can't just disappear from the picture or take Seju's place and have her own "side-story" going on because she was the protagonist and related to Sumin from the start. Also can we just forget the healing story thing? I think the author changed there mind, I don't see one healing this about this.
Honestly, both TeamPink was never in a good position and TeamBlonde is going downhill... This might go TeamPink route for a while but I doubt it'll stay like that.
Likely scenarios according to moi :P (ordered from less likely to more likely(the letters are in the same likelyhood))
1. Either Sumin will be cheating on Sungji; so Sungji won't be irrelevant.
2. Sumin won't cheat. She will decide to choose Seju in the very last chapters so Sungji will still remain relevant.
3. Sumin will break up with Sungji because of Seju. Sungji will somehow end up in Nami's hands and might show a bit of a less innocent side.
3a. the same but Seju will also not want Sumin and will befriend Sungji which might lead to some sort of planned or unplanned revenge. (involving Nami)
3b. Sumin will realize she still has feelings for Seju. Sungji will decide to help her reconcile with Seju instead of pursuing her (Sungji, don't be a Mary Sue, please).
3c. Sumin will realize she still has feelings for Seju. Sungji will pretty much turn into another Seju who doesn't care about what sort of relationship she has with Sumin as long as she has one so they break up but they still are fwb. Polyamory sort of ending but not exactly.
3d. Sumin breaks up with Sungji because she has feelings for Seju. Sumin will realize she can't get back with Seju because their relationship is broken but can't be with Sungji either because she doesn't love her enough and it's not fair to her. Sumin has been healed of her past wounds but feels lost deep inside. Sungji decides to stay by her side as a friend and they decide they might get together again when Sumin gets over Seju for good. In the meantime Sungji also befriends Seju and decides he friendship with her is more important than Sumin's love. Also Nami could be involved in this scenario, sleeping with Sungji and confusing Sumin at first or sth.
3e.(yay, my first name letter, this is a good scenario XD) Sumin realizes she hasn't let the past go yet and she still has wounds from when Seju cheated on her and that's why she can't leave her alone. Sungji takes notice of Sumin's relationship with Seju and gets really hurt; Sumin realizes her mistake and feels that even though she hasn't cheated on Sungji is likely hurting her as much as she was hurt. She slaps herself and runs to Sungji and pleads forgiveness. Nami getting involved with Sungji is also possible in this scenario >.> Sungji getting jealous of Sumin being bottom when she did it with Nami and feeling like Sumin has a delicate side she is not able to cater to or sth (drama basically)
if an approximation of these doesn't happen, gosh, I bow to TeamGaji. They will have a very vivid imagination or pull some ending that will destroy us all.