Art is amazing, there are so many small things that can come back to bite you later if you don't pay attention to it.
The characters are absolutely amazing, and each of them is unique in appearance. They're not stiff at all with their personalities. The author is an absolute genius.
No matter how serious it gets, there's always something to laugh at, the comedy is amazing. It flows so well.
The art starts out above average compared to what you'd see in most beginning comics (ones without professional artists, and just the author working alone) and then just blossoms~
The concept is pretty unique, and the story does a good job at displaying a "Gray versus grey" kind of setting. There's tons of lore and it does a good job at pulling epic plot twists, and the series just builds itself where even weird stuff seems normal.
I forget all the other stuff I was going to write. 0w0 I got distracted by food.
Tell me a reason to read this series. 400 chapters are not short at all