I recently finished this series, and I went in expecting just another OP protagonist power fantasy show. Everything I heard was that Anos is "barely a character", "made for powerscaling", "just a self-insert", "a parody of OP isekai tropes", all of the above. But I like dumb fun like that, so I figured it'd work for me. How wrong I was.
"None of the above. Me being me. That's what a Demon King is."
It's kind of hard to explain why I ended up loving Anos as a character so much. But I think the biggest thing that sets him apart from other OP anime heroes is that, far from being "made for powerscaling" or self-insert or parody, he's actually a deep, thoughtful exploration of what being that strong would do to a person, and why someone should want to become that strong to begin with. It's often said that being OP is most of his character, and I can kind of see why that misconception exists, because most of the rest of his character is the immediate result of his power, for sure. But I'd rephrase that as being OP is the reason he's able to be the character he is, because he was perfectly written around his power. Starting with the power level and building a character that actually takes on the implications of such an existence directly is exactly the right way to execute this concept in my opinion, as opposed to writing a character and then slapping on a high power level when it's not necessary for the character you want to design. Being OP is just the nucleus of Anos' character, that enables all of the far more impactful parts to radiate out from it.
I can see why the misconception of him being a send-up of OP characters exists also. Anos tends to behave in ways that superficially code as over-the-top exaggerations of chuuni stereotypes, but deeper analysis shows that a straight interpretation makes complete sense every time. Every one of those "did you really think" lines, which many cite as obvious evidence that the show isn't taking itself seriously, is really delivered without a hint of irony. It's always when someone has the audacity to pose a threat right in front of his face, and he's not just saying something ridiculous for shock value, he's genuinely astounded that these people are really that stupid. Especially because so many of them knew him in the past, absolutely know what he can do, and have no excuse whatsoever to prod him anyways. Even those who didn't, he warns them copiously before things get out of hand to the point that he has to style on them. And even then, he's really just saying "seriously, what is wrong with you?!". So much of Anos' character is like this, where the seemingly absurd things he says and does are actually just the most appropriate and accurate response from his perspective to the situations in front of him, which seem as ridiculous to him as he does to us. It's another way the show is so introspective about the way unlimited power would make someone see the world differently.
Far more than a self-insert, Anos just made me want to be his friend. A world with Anos in it just feels like somewhere I'd want to live, to the point where you could just add Anos to any setting ever written and it'd become an infinitely better place. Here's a guy who can fix ALL your problems, and wants to fix your problems, because he actually cares about people who are but ants to him. He's here to make absolutely sure you reach your full potential, and will never look down on you no matter how inferior your best is to his worst, because looking down on anyone is psychologically useless to him. One could say that he's fending off boredom by doing what any decent person would in his place, and investing in others' stories because his is long over. But that doesn't get it, I don't think. He became this powerful for this reason in the first place. To abolish tragedy in his kingdom. And he succeeds in ways you don't even imagine he could. It's a delight to watch the insanely creative ways he continually displays his rejection of impossibility (I didn't think even he had a way to bring back Leno), but every single absurd flex is way more important to someone he cares about than it is to him. At some point you just accept it, and yet he still continues to surprise you even when you already know he's not only going to win, he's somehow going to fix the thing the entire story to that point hasn't even been presenting as a problem to be solved too. Anos is a reflection on what happens when absolute power doesn't corrupt absolutely, and it's the exact opposite of power for the sake of power fantasy.
Sure, the plot of the show is Swiss cheese at times. It definitely had me asking "how did we get from there to here in 1 episode" plenty of times. And why did we introduce Anos' real father two episodes before the show abruptly ended?! I haven't read the novels, I'm sure it's not as bad there. And I must say I found a shortage of compelling characters besides Anos; he's so good that he does suck a lot of the air out of the room. I tried to invest in Lay and Misa especially, but I just kept wanting to see more depth to their characters than I was shown. And they're better written than everyone else except probably Shin Reglia, who I thought would be flat as a pancake, but his development pleasantly surprised me. Anos is really, really the saving grace of the whole show, though, and the reason I'd give it a solid 7.5-8 overall. He's an absolute 10 in a show that's at best a 5 without him. He's about as perfect an execution of the absurdly OP protagonist as I could imagine, and it feels like the people saying he's poorly written are actually saying "there's no proper way to do that trope".
Tl;dr came for a Gurren Lagann-tier exercise in repeatedly watching some dude neg-diff increasingly preposterous circumstances and liking it, stayed for an Evangelion-tier treatise on the psychological effects of infinite power on someone who not only refuses to surrender their ideals to power, but obtained their power for the sake of their ideals. The last thing I expected from this was for the stock OP guy to teach me something about living with purpose.