I would've put it at least C-tier if it wasn't for those sudden raps after the drop.
K-Pop Source — Keeping the K-Pop Forum Spirit Alive
Dreamer_of_Songs
litc
Tbh I really liked that part 
At first I was thinking "Oh no not a boring ballad" (not that all ballads are boring) and then that part came and I loved it, it was interesting, and the vibe. The delivery of the lines, the dark and mysteriousness, the instrumental during that part. And the rest of the song is fun, but there's still that chorus (I think the would you kiss me? oh oh oh part is the pre-chours) and I love it so much
It's beaten out you got for my fave bside atm
At first I was thinking "Oh no not a boring ballad" (not that all ballads are boring) and then that part came and I loved it, it was interesting, and the vibe. The delivery of the lines, the dark and mysteriousness, the instrumental during that part. And the rest of the song is fun, but there's still that chorus (I think the would you kiss me? oh oh oh part is the pre-chours) and I love it so much
It's beaten out you got for my fave bside atm
Dreamer_of_Songs
My favorite B-Side will always be Babyface and I realize I have so many ballads for S-Tier (something about WJSN's ballads makes me feel calm).