tl;dr

Okay, I'm not even watching this show but I've seen screenshots of this guy choking his wife and telling her death threats...

"such a standard for cdramas green flags"

I am watching it and at no point (up to ep 16 of 28) has he choked her and the closest he has come to death threats is pretty early on in the show when she was accusing him (entirely unjustly) of being all manner of horrible things and he, somewhat understandably, told her that - to paraphrase - if he were anyone else, saying such things would land her in a whole heap of trouble. Did he do so in a rather threatening manner? Absolutely. Did he genuinely threaten to kill her? Absolutely not.

As far as cdrama MLs go he is fairly standard - he is definitely manipulative and somewhat unhinged (he kills people but ofc they are bad guys and deserve to die) and he absolutely started off seeing her as just a pawn in one of his (with noble purpose ofc) schemes... but he is also the only person in pretty much the entire show who respects her as a person and respects her agency and insists on her being free to make her own choices (even if that choice means she will leave him). Something literally no-one else - not her dad, her mum, or her original sweetheart - has done.

forced her into marriage as part of his political plans, with no opinion or interest as to whether she's OK with it. Just because he may have gone in with 'ah, I will give her a divorce later' does not negate it in any way. Even if we go with 'oh this is not really historical' doesn't help - if this is a proper period setting, he's fucking with the woman's most important choice/action in life but if it's ahistorical modern dress up and marriage matters less, then all the murder/choking/death threats/etc is not excusable because in a modern person playing dress up they are definitely not good.

repeatedly physically threatens her. He may mean some of it, he may not, fact remains, she's a woman half his size and with no battle skills.

is rude and insulting to her and just acts awfully to her whenever he thinks she's meddling into his family affairs (she is his wife, mind you.)

All the threats culminate in him freaking out she'd reveal his temporary blindness, choking her - literally grabbing her by the neck - threatening to kill her and to destroy her reputation.

his other wife justifies all of this by saying hey at least he's not worse and it doesn't matter if he has a temper as long as it's with his loved ones (which reminds me of the old Russian folk saying "if he beats you means he loves you.")

Now, do I care he's red flag/toxic/ other term du jour? Heck no. My favorite character last year was possibly Di Lin from Eternal Brotherhood 2, who massacred whole villages of civilians on his march to rescue his brothers so the news wouldn't leak. I don't even care if the characters are toxic vis-a-vis a partner. I love me toxic fictional dudes - I am salivating for Overdo to drop and both ML and FL in this one make this dude seem a saint (and the same goes for every FWSC adaptation ML and some FLs) and I enjoy my minis where half of them appear either ML is torturing FL or FL is torturing ML. One of my top 5 cdramas this year was Generation to Generation and ML is a certified headcase; we are not even going to get into what kind of games the bulk of characters of Veil of Shadows, my favorite drama this year and probably in my top 5 of all time, got into.

But as you say, that's not relevant (to me) to enjoyment of the drama and to whether he is an interesting character.

As for his nastiness in the beginning, one of his primary traits is willingly playing the monster in other people’s stories if it helps the greater good. There’s a reputation he’s protecting. That’s not to say it’s okay, but rather to point out it’s based in a character flaw that is being criticized and interrogated by the narrative.

I, too, was and still am uncomfortable with the ages of the leads. What is making it work for me (so far) is that the ages match the characters’ relative life experiences (no more 19-year-old grizzled generals, please) AND ALSO a primary theme of the entire show is the young woman, Jiayu, being able to make her own choices and live a life she picks for herself.

This is not to say the show doesn’t have dodgy moments, but like everyone is saying: screenshotting those dodgy moments out of context isn’t a great way to gauge the show.

The conflation of overall likeability (this person is a green flag/not a red flag) with their specific actions is the reason we get people trying to offer apologia for standard abusive actions like strangling someone -- because they like the character doing it.

As we can see from this chain, this conflation leads people to using a term for analysing real-world behaviour for warning signs for intimate partner violence with the norms and tropes of fiction, introducing a moral relativism ('no cdrama lead would be a green flag then!') which is antithetical to the initial purpose of the term.

Strangling someone is a red flag action.

It doesn't matter if it is a common action by cdrama male leads, or if those actors make it look sexy, or if there are cdrama characters who are more extreme in their violence. If 90 percent of men in a society strangle their romantic partners, the fact that it is the norm would not negate the fact that such an action is intimate partner violence.

And personally, I find added context* which boils down to 'but he was really upset at the time' more than a bit stomach-turning given the origin of the term red flag when assessing men in their romantic and sexual relationships with women.

But also - I keep wondering how much conflation of action and character has to do with the newfangled tendency to assign moral value to your entertainment and to treat fictional people like real people.

I think a lot of “but no, X is a green flag” I see around stems from “I like this character/I am sympathetic to them/I think they should have a happy ending etc etc” tied together with “I have to like only moral characters because only immoral people like immoral characters.” So a character has to be a good person and in that view a good person also only does good things. So people try to justify as to how the character they like does only green flag actions and is a green flag and all around good person for that reason and that’s how we get comments like “Xie Wei from Kunning/Xiang Liu from LYF etc etc is a green flag” (while at the same time contorting yourself into a different pretzel as to how the character you don’t like is somehow problematic and a bad person.)

And I always found that bizarre. It’s fiction. No real people were harmed. What kind of set up you like in your fiction says nothing about your real world values. I don’t find anyone in Key particularly interesting but I am currently enjoying the hell out of Overdo and both of our mains are terrible people who’d definitely earn the red in any discourse. So what? They are fictional, so who cares. I am rooting for those crazy murder and choking kids to get out of it alive and mess with each other for eternity. (And sometimes when I am super into a character who does awful stuff, I don’t even wish that! Li Chengyin of GMP is one of my favorite male leads ever and I only wish I could erase GMP from my brain so I could watch it for the first time again. He’s also a monster and a rapist and I both ship him and hate him and am so so so delighted by the ending he gets which is a punishment that might as well have been perfectly tailored to him.)

Conflating fiction with real life and what tropes you enjoy with real world morality is how we get all the beige entertainment but also people patting themselves on the back for being good people for enjoying unproblematic fiction and therefore not feeling they need to do anything more in terms of actually making the world better in real world terms.

"But to fall in love does not mean to love. One can fall in love and still hate." ― Fyodor Dostoyevsky

D&D Forgotten Realms - Adventures in Faerûn

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