I've been binge reading this all day and I gotta say, I am loving this. The character designs are top notch without going overboard, the characters themselves are lovely and I am really into the mystery vibe going on. To me, this is like the Korean MHA, except more grounded. Plus, the action scenes are super cool and carry a lot of weight in them. Everything feels powerful, as it should.
I like how the MC is getting stronger as his body adapts to Justice's powers. At some point, he'll be as strong as Justice in his prime. Speaking of Justice, it's clear that he suffered from some kind of injury or disease and that's what's been making him weaker. He was trying to prolong it as much as he could, but died in the end at his weakest. But the MC doesn't have that same issue; he's slowly growing and soon, will be stronger than Justice. That's neat.
Bone guy is really nice and the Shadow girl's powers are rather unique. I mean, I've seen some iteration of it before but it's still rather uncommon. Overall, I consider this a solid 9/10. Not a max rating yet because superhero genres are rather forgettable at times but there's no negatives as far as I'm concerned.