I think Creepy will go the way of secondary girl's Mom in Pick the Stars and end up a corpiscle by the end. I agree there is no way there can be a happy ending while he's alive (even if the final OTPs ended up KS/YS and JJ/DA) but I doubt he's making it out of this still breathing.

I think the "they are perfect for each other" thing is not really in play except maybe it will cause a misuderstanding/they'll try to make a go for it - I have never seen a drama switch OTPs after the sort of set-up they have JJ/KS nd DA/YS.