Suyin Beifong is such a weird character narratively
In many ways, she's the weirdest character in ATLA or LoK in her place in the story, considering her actions and beliefs. Let's just walk through everything.
Suyin got herself involved in criminal activities and street gangs as a kid and helped rob stuff. Then she scarred Lin when Lin tried to arrest her for that. And the fallout from that is implied to have led to Toph retiring.
After that, Suyin was sent to live with her (extremely wealthy) grandparents. After a while, she left them and began traveling the world and trying out various things, including being part of a traveling circus, living in a sandbender commune, and joining the crew of a pirate ship. Note that pirates rob and kill people. Note also that Suyin seems to have felt just about zero remorse for any of the above, and expected and demanded that Lin forgive her for everything without getting an apology.
Eventually, Suyin had had enough of all the traveling and robbing and killing and circus performing, so she used her vast, vast family wealth and bought a plot of land to build her own city on.
Zaofu seems to be essentially a Beifong family dictatorship defined by Suyin's ideological beliefs. As far as I can tell, the guiding principles of the city are "progress," "modernity," harmony, order, and control. After all, as Suyin says "Thanks to Aiwei, there are no secrets in our city," and she evidentially likes that a lot. The degree to which Suyin values absolute control over her city can also be seen in how incredibly outraged she gets when Kuvira, Baatar Jr., and some other citizens decide to leave on their own initiative. Her anger at Aiwei's betrayal ("I want you to hunt down Aiwei and bring him back to me") also fits the same pattern. Interestingly, Kuvira always claims to have gotten 90% of her fascist ideology from Suyin and Zaofu, and I actually think she was telling the truth, that Zaofu was a city organized on proto-fascist principles and Kuvira merely applied its principles to the wider Earth Kingdom.
Now perhaps we should turn to Suyin's relationship with Kuvira, which always seems very odd to me. Suyin took Kuvira in when Kuvira was a young child and trained her and claims "Kuvira was like a daughter to me." Yet Suyin never seems to really treat Kuvira like a daughter when the two interact on screen, nor do Suyin's children seem to see Kuvira as a sister. Notably, when Suyin introduces her family to Korra, she doesn't include Kuvira, nor is Kuvira invited to the dinners with Team Avatar. It's all very weird.
Anyways, Korra first arrives at Zaofu, Suyin seems to expect her, the Avatar, to stay in Zaofu relatively permanently to personally tutor Opal in airbending. The idea that Korra has other important responsibilities which don't involve personally serving Suyin's interests doesn't seem to cross Suyin's mind. We also find that Suyin is sheltering Varrick and Zhu Li, awful, highly amoral criminals, from justice since they're useful. On the plus side, Suyin is willing to personally teach Korra and even Bolin metalbending. She even eventually offers an apology to Lin for her behavior when younger, an something which helps reconciles the siblings. Suyin even allows Opal to leave for the Northern Air Temple.
Then the Red Lotus attacks, Suyin helps drive them off, etc. Everyone realizes that the Red Lotus had inside help, Suyin uses Aiwei the lie detector to search for the traitor, it turns out Aiwei was the traitor, he flees, Suyin is suitably outraged, and so on. Then we get to something "interesting": Korra wants Team Avatar to go after Aiwei, Lin (correctly) points out that this is way too dangerous, and then Suyin lies to and deceives Lin to make her think Suyin agrees with her and go bed, before personally sending Team Avatar after Aiwei anyways, something which goes very poorly. Suyin and Lin have barely reconciled, and practically first thing Suyin does is lie to and manipulate her sister. And yeah, Lin is pretty pissed that Suyin "stabbed her in the back" next time they talk, but essentially the entire thing blows over with zero consequences for Suyin.
The next thing that Suyin really does in the narrative is lead Zaofu's security forces to help Korra, Team Avatar, Lin, and Tonraq take on the Red Lotus and rescue the airbenders. This is objectively a good thing, but it's also interesting, considering what we later learn about Suyin's isolationist beliefs. However, it's worth pointing out that Suyin had several personal motives for her actions here: Her daughter Opal is one of the airbending hostages, Lin her sister is evidentially going to be involved, and the Red Lotus had the temerity to attack Zaofu and Suyin is probably pretty pissed about that. Without these "ulterior" motives, I doubt Suyin would have been willing to get involved. Then Suyin helps everyone else defeat the Red Lotus, but doesn't really do anything too interesting as part of that. Cut to Book 4.
What Suyin mostly does through Book 4 is oppose Kuvira, but we still get some interesting material as part of that. We learn that Suyin was asked to help stabilize the Earth Kingdom between books, but she refused. Considering how the children she raised ended up handling things, it's very likely that Suyin would have ended up becoming a (bigger) fascist dictator, so Suyin's refusal is also probably a good thing, even though refusing to provide aid to a country in anarchy probably isn't the best thing.
Kuvira and Baatar Jr. disagree about this, and they leave for Ba Sing Se with "Varrick, my security force, and a few of Zaofu's wealthiest citizens." Suyin is so outraged she responds by declaring them (or at least Kuvira) exiles, forever banished from Zaofu. We also see the start of a couple tendencies which will reoccur in the season. These are Suyin blaming Kuvira for Baatar Jr.'s bad actions and Zaofu's citizens being pretty OK with Kuvira and her actions, while only the Beifong family hates her.
Next time we see Suyin, it's at Prince Wu's "coronation." Normally Suyin would absolutely despise a royal idiot like Wu, but she hates Kuvira so much that she's willing to join the other world leaders in imposing him on the Earth Kingdom (as a useful lackey?). After that doesn't work out, Suyin tries to convince Kuvira to step down, something which goes poorly.
A couple episodes later, Kuvira shows up with an army and demands Suyin surrender Zaofu, something that Suyin understandably is pissed about. Mutual recriminations result, Suyin again blames Kuvira for all the actions of her fascist dictator son, and so on. Korra tries to continue negotiations, but Suyin has already left to try to assassinate Kuvira in her sleep. That's maybe a reasonable reaction to what Kuvira is doing, but it's an odd way to treat someone who is "like a daughter" to you. There's also evidence that Suyin doesn't really get that people are legitimately loyal to Kuvira and legitimately believe in her ideology, or that Baatar Jr. agrees with Kuvira, is equally complicit in her policies, and would continue leading the Earth Empire in its conquests if she died. Anyways, Suyin's attempt fails, she ends up captured, and ultimately she's forced to watch Zaofu's citizenry bow to Kuvira and cheer her. Although there was still coercion involved, the fact that only the Beifong family refused to bow is still evidence that the "Metal Clan's" general population has a reasonably positive view of Kuvira and her ideology and the only reason the Beifongs don't is because they have a personal vendetta against her. After all, Kuvira's ideology derives from Zaofu.
After that, Suyin doesn't do too much, narratively. She escapes with her family from Kuvira and Baatar Jr.'s prison for them and she opposes Kuvira's attempt to conquer Republic City. Again, that's objectively a good thing, but Suyin opposing it also makes perfect sense given the depth of her vendetta against Kuvira. The only interesting thing is that Suyin instantly forgives her fascist dictator son and doesn't hold him the least bit accountable for his actions, while continuing to hate Kuvira after she apologizes. Again, more evidence that Suyin does not, in fact, view Kuvira as a part of the family.
Overall, Suyin is narratively very weird. Based on all that I've discussed above, it's clear that she's very much not a good person, nor is she particularly likeable. She basically runs a mini-fascist dictatorship, after all. Yet Suyin not only gets a massive amount of narrative attention (it seems like some of the writers really liked the idea of her and her family), but is always an ally of the protagonists and is never held truly accountable for her actions. Considering who she is as a person and her backstory, having her be an antagonist or villain would in many ways make more sense, but that's not the route they went.
TLoK was really into giving its antagonists half-assed redemption/quasi-redemption arcs (Tarrlok, Desna and Eska, Varrick, Zhu Li, Tahno, Zaheer, Hiroshi Sato, Baatar Jr., Kuvira), but Suyin doesn't really fit into this paradigm, since she was never an antagonist in the first place. The only characters across ATLA and TLoK who really remind me of her, in terms of being bad people who are never really called out by the narrative, are King Bumi, Varrick and Zhu Li, and Iroh.
Of these, King Bumi is a complete dick, but he's a much more minor character than Suyin and gets away with a lot due to being a "comedy" character.
Varrick is an absolutely awful person, but the narrative lets him avoid consequences for that since he's likeable and funny. Zhu Li really just tags along with his narrative.
Iroh is morally grey at best in the present and morally black in the past, but again the narrative avoids calling him out about it since he's funny and likeable and nice to the most audience sympathetic character, Zuko. The narrative even starts painting him as perfect and a saint after a certain point, something which continued in TLoK.
Suyin isn't like any of them. She's not a comedy character. She's not funny or likeable. And it's not like the narrative paints her as perfect, like it does for Iroh. She sometimes suffers the consequences of her actions, and I think she's supposed to come off as significantly flawed. On the other hand, the narrative never really calls out Suyin for any of her terrible behavior, bad actions, or general bullshit. She's never held truly accountable in any way for anything. It's all very odd.
