
That's not any logic, that's writer logic.
Being alive just because you're the main character for the whole story doesn't keep the author from finding a way to kill you in the end, it's actually even easier to kill the MC when the only reason they're alive is because they're an MC, you have to put less effort into making it coherent which is great

Whether you took it from yourself or from blondie doesn't mean he won't die honey. As a writer myself I'd know, just because someone is "your main character" doesn't mean you're not killing them.
On the contrary, if blondie thinks of it as a story, there's even more reason to believe that he could die. So you should definitely follow that advice that we always give to kids and teens: "don't repeat things that you don't understand" especially not to support a point.
I went off, thank you, your intervention was fcking useless, goodbye.

[Warning: this turned out long / guess I find this topic pretty interesting and had too much time on my hands ╮( ̄▽ ̄)╭ / so feel free to skip or whatever]
You're right, there is, theoretically speaking, a certain chance of the MC dying *in some way* at the end of the story - though *only* at the very end, for obvious reasons. Earlier, you were arguing about how it could happen in the current situation, about how the killer could make it seem like an accident, etc. - with regard to the situation *now*, at ch.16 - which, logically possible or not, can't happen even if that was what Seo had in mind, because – again, *plot armor* ╮( ̄▽ ̄)╭
But let's say it's a theoretical possibility that the MC could die at the end of the story (though we're absolutely not in a position at this point to have any idea about how that might come about just yet, because circumstances are bound to change and develop one way or another before the ending).
That said, here's the thing. Objectively speaking, from what I know about manhwa authors of reasonably popular works like this with a fairly wide reader base – it's a fact that there is on average a pretty overwhelming tendency to, if (morally and otherwise) reasonably possible, keep close to what the majority of the readerbase wants to see happen, or at the very least a general tendency to avoid things that would be known to outright 'piss' a vast majority of the readerbase 'off'. This seems a bit different with e.g. novels of genres like this, but with popular manhwa, you generally see them *if possible* keeping its content somewhat tailored to the preference of the audience. (I imagine it's in part a matter of finances and revenue).
And the "problem" with Ah-in in this regard is obvious – he's a character with an overall high percentage of likability to most people – on top of that, with a sad childhood including neglect and abuse, and basically being treated poorly by everyone his entire life up into adulthood despite always looking for affection. Aside from some controversial details that overall only serve to make him more lifelike and thus more likable, he's pretty much a classic case of a character designed for the audience to feel sympathy and root for.
So unless things change a lot from how they are now, realistically speaking, I see no reason why the author would be aiming to "shoot themselves in the foot" that drastically by needlessly aiming to kill a character that was so obviously designed for the audience to side with. Especially the killer of the story ultimately “simply killing him, end of story” would probably not go over well with the majority (I know I'd find that extremely underwhelming as an ending, even aside from liking Ah-in as a character, because it would make the entire rest of the story until then seem pointless). I guess both dying together for some reason or other seems slightly more realistic as a possibility?
But still. With the way we've been introduced to Ah-in's backstory and the way his character is right now, I'd still say there's a >95% probability it likely won't be happening.
But just to be clear. I understand your preference (though I don't share it ;), and that it's simply your personal taste in fiction. (Because I'm going to assume it's not you merely trolling the other readers here, because that would be just too mean / immature.) I've understood from your comments that this is simply something you as a reader would very much like to see happen and that you are rooting for, and as someone who also sometimes roots for very unrealistic and unlikely outcomes, and is also occasionally in the minority with what I'd prefer, I can respect that.
All I'm saying is, objectively speaking, I wouldn't hold my breath for it to happen, if you know what I mean (current story reference intended ;).
But I may be wrong. ╮( ̄▽ ̄)╭ Guess we'll just have to wait and see. ;)

Damn it seemed long but it wasn't that much. Well in my topic and replies I always talk about the future and the end of the webtoon I know that in the current situation he cant kill him, but I wont lie saying my opinion about the ending no matter how far it may be, is not completely influenced by my burning desire to see him kill Ah-in lol
Get him killer blonde lol kill that dumb mf. I really like the killer's vibe lol I wonder how he will kill Ah-in