@TLC:
I cannot believe the number of people who hate the Kanjuro traitor plotline. I will be the first to admit the follow up to his character has been very frustrating with the constant fake out deaths ( a consequence of Oda rushing the story for the 1000 chapter mark) but the actual execution of the reveal was objectively brilliant.
I think we have different definitions of refreshing considering this is basically the default implementation of traitor plotlines. And obviously very different definitions of "objectively". Anyway, I'd like to respond to everything else you said in more depth, but since this is not a One Piece thread I'll refrain. I'm just gonna elaborate a bit more in my reply below and probably leave it at that, as least as far as One Piece is concerned.
@zeltrax225:
Well TLC pretty much brought up the points I was about to make so in addition to that, I am genuinely curious what then you would consider a master class in "traitor writing". Kanjuro was logical and could have been guessed from an observant reader, his role as a traitor was so significant that every character involved was affected and his role was deeply consequential. Orochi who planted him actually see the importance in him and utilized him pretty well, doing stuff that manipulates and further his hatred. AfO literally just sees Aoyama as a broken lighter and it's actually kind of stupid that he wasted such a good chance to actually plant someone that shares his views or at least attempt to manipulate and shape Aoyama, but he straight up didn't just so he can pull off that cool one liner this chapter.
Maybe Kanjuro is no masterclass, which now I'm curious to hear who is, but he is certainly a lot better written than Aoyama.
I don't have an example off the top of my head, but I can at least tell you what I didn't like about Kanjuro. Outside of his awful handling after the revelation, which I guess you can argue is a separate issue, what I didn't like about the buildup and reveal itself is that it was basically treated like an afterthought. Like desa said, it basically amounted to someone bringing up a hunch once and then barely ever talking about again. Were literally any of the Strawhats aware of this traitor's supposed existence?
Additionally, the reveal happening just because Kanjuro decided, for some reason, to give himself away is dumb. It would be much more impactful if we found out he was the traitor in action, i.e. actually getting caught off guard by him sabotaging the group at a critical moment, like stabbing Kiku or something. You know, like Squard, in the very same series?
Furthermore, his characterization and motive are lame and generic and could basically be used for anyone. Oh he doesn't have his own ambitions, informed by his own relationships and emotions, but is just following orders? And his reason for doing so is because he is suddenly related to the villain, something which wasn't foreshadowed at all? Great, you could literally paste this template onto any character and have it work just as well, because it's so detached and impersonal.
Lastly, but frankly most importantly, I don't give a flying fuck about Kanjuro. How could I? This issue permeates the entirety of the scabbards with exception of Kinemon and Kiku, but they are just extremely poorly developed characters and I don't feel endeared to them at all. Further casualties of Oda's increasingly bloated arc casts. I suppose I do care that Kinemon is distraught about it then, but it's not like his relationship with Kanjuro was given any special attention. So the scabbards feel betrayed, but why should I?
So let's see how this compares to Aoyama (which for the record, I still agree is worse). First things first, people predicted Aoyama too. The hints were there, so I'm not sure why we'd count that as a point in Oda's favor. And while I agree that his actions weren't as impactful as they should've been, they still led directly to Bakugo's kidnapping, the Kamino fight, All Might's subsequent retirement and the crumbling of the symbol of peace. About as impactful as Kanjuro in the grand scheme of things.
But notice how all the other points I mentioned reflect in MHA's reveal too? Plotline that's barely given passing acknowledgement - check. Giving themselves away in low stakes casual convo - check. Generic circumstances that could literally be lifted onto any character, rather than being motivated by their established backstory, personality and relations - check. Nobody side character with barely any development that I don't care about - actually, I'd give this one to Aoyama! At least he's the main character's friend and we spent a chapter establishing that. And his situation is more tragic to me because he was forced into it and can actually explain how that makes him feel and why, rather than being some perfect boring emotionless actor.
So really these two cases are not so different after all. Certainly not to the point where one could be giving tips and pointers to the other.