OK, my feelings about this manga's art varied a lot.
For the first 20 chapters or so, it reminded me a lot of what I've seen of "I am Hero", by that I mean, every expression is unbelievably ugly, everyone looks like a poor man's caricature, everything constantly looks off, and staying on size-reference isn't a thing. It's detailed, but the details are all wrong.
This slowly (and very slowly in the case of character heights being consistant) starts to get better, and the art finally finds it's own place around 30, peaking from around 50 to 100.
After that point, it quickly starts to degrade in quality, becoming a lot more simplistic, removing details, it doesn't go back to being bad or what makes it unique, but it does get a lot less visually interesting.
Now that that's over with, I can say what I actually think of its art as a whole. I liked it, quite a lot. It's distinct and the visual designs are absolutely top tier, all of them are simply amazing and they tell you all you need to understand about an ability at a glance. I also really like what we are shown in the pannels, not how it's being drawn, but what is being drawn, I think there are a lot of cool ideas in there. Appart form that, I should note that this manga really overuses explicite visuals, not a single major female character isn't shown at least once having sex, and while in some cases, like the fractured human who wants to be loved or the wannabe Jagan, showing sex is warranted, in most cases, there is no need to be explicite like the artist was here, and it gets very annoying, very fast.

The characters are really good. I liked all the villains, I liked all the heroes, I liked all the in-betweens, the owls were all super fun, but a lot of it is underused. For instance, the owls, they get very little screen time after we get into the story proper, which is really weird considering how much they are setup. Same with triple H, after chapter 50, the person who runs it just disappears, never to be seen again, while healing girl keeps being used for the purpose of being a dispenser from TF2, but without any development to her as a character or to the story trough her desires, which start to be completely ignored after that point. Still, the cahracters are good, they're well written, and I think they bring up a lot of fair questions about morality in interesting ways, I also love their designs, not only their visual designs, but also their ability designs, this is what the monsters from Sweet Home and Shotgun Boy should've been, they all are clear and distinct, they all look great, and they are all given a proper reason to be. Though, I do think there is some lost potential in the later chapters with overwhelming desires, in the early ones, when Jagaan or someone else lets loose, we see them transform in very obvious ways, and this slows down in the later chapters, with transformations mostly becoming what they already were when under control, but for their whole body.

The story is really good too (outside of the pointless sex scenes)! I think the author really pulled off the idea of a pointless hero well, with Jagaaan's goal, beliefs, and ideals constantly transforming and Jagaaaan himself questioning the validity of those desires. The story "moves" independantly of Jagaaaaan, who just gets pushed along, which I would usually dislike, but that's also really well done here, with tree-man serving as a in-universe reason to properly explain why Jagaaaaaan specifically has to do things rather than someone else, making it feel a lot more natural than you would expect for a story with a main character that always ends up in the center of everything. There's also plenty of tension (until the last 20 chapters), with impactful character deaths and plotwists up the wazoo, keeping the story interesting all the way. There were only 2 things (outside of pointlessly sexualising every female character, which I already mentionned before) I really had problems with in the case of the writting, the first one being small plot holes like how famous criminal "Jagaaaaaaan" is able to get G-balls (and how they just completely stop being a plotpoint after the end of the arc with triple H), or how the fractured-human who wants to be loved could freely turn back and forth without ever needing a ball or getting a bird even if he got a real frog/baby frog instead of a half-frog, and the ending, which starts off feeling more like a "conclusion" than a "climax" or "finality", just closing plotpoints left and right, before pointlessly overextending the final fight for 7 chapters and doing an epilogue which opens EVERY SINGLE PLOTPOINT AGAIN, making the whole "ending all of the plotpoints" thing just useless.
I like the use of different themes like depravity, selflessness, selfishness, stress, supression of our feelings, power (literally and as in hierarchies), fulfilment, etc. The author really used a lot of different themes and ideas, but I still think he was able to develop each one completely, never letting any of them feel underdevelopped.
The pacing's a little wonky too, there are not super hype moments, but cool moments do happen, the setups are good, but the problem is that the climaxes are usually very long, making them a lot less impactful, the drama parts are often good, but they are similarly over-extended, leaving each individual heartwrenching choices that are forced upon characters with less time to truely take their place and leave their mark on the reader.

Low to mid 7. An overall flawed, but enjoyable reading experience.