There's a messy way to love for these two.
At first, Yiseok is obsessed with Cocaine, but there's something that happens that differs Yaba from Cocaine. Yiseok cannot live without Yaba by the end. But a great deal has to do with how Yaba's abilities are blatantly used for manipulating Yiseok's brother into death. That's an interesting read.
Does Yaba succeed?
It's not love. It's obsession. Think about it like a junkie and a drug. There's evidence that there might've been something going on (calling Cocaine to hear him sing or swimming to be right in front of him) and some other stuff, but it's definitely not love and it fades fast because of Yaba and the ML's interactions from a certain point on. Cocaine is not innocent. After a certain point, it's outright contempt.

Saw reviews on Novel Updates and many said the ML is trash and ngl he kind of is so far
I was wondering if novel readers could give spoilers on the relationship Yiseok has with Yaba and how it progresses? Do they vet together and stuff etc.? Especially since Yiseok is a perverted playboy and liked/uses Cocaine