Bum's bum

I never thought I'd say that about this mahwa because it was always so good and satisfying for me to read it with all the tension, the plot, psychological issues and everything, but I really don't like the last few chapters. I think it just went downhill after Sangwoo's mental breakdown, the story is too rushed, kind of not very well thought through and I have a feeling that Koogi had a different image of the ending before and now, I don't know, somehow shortened it? Or changed it so that she could end it faster? I thought it was supposed to have more seasons and now there's only one chapter left split into two parts... I'm willing to understand if the reason is her health problems but I can't help but to be disappointed.
Also the quality of the dialogues in the last two chapters and the whole fight.. I just can't help but laugh. And the mistakes.. the explosion happend in the kitchen which is on the ground floor as it can be seen from the entrance, but Bum who's outside the house, looks up and sees the explosion and flames coming out from the first floor which is if I remeber correctly a Sangwoo's bedroom..? And a boiling water spilled on Seungbae's face.. Why didn't it burned his eye? It just makes less and less sense... And I still have so many questions, like why did Sangwoo keep the fake nails in his drawer? What did Bum bought with the borrowed money and what was he hiding from Sangwoo? Why didn't Seungbae learn anything and came to Sangwoo's house unarmed, with no plan and then even destroyed the only evidence that he had against him?
And it's a shame to see it like that cause it was one of my favourite mahwas and I always thought that it would keep it's quality till the very end.

Are Ivan and Alec brothers? Cause they have the same surname...
I smell drama