A pretty good manga if you end it at around chapter 100 (Modern day arc) would have given it a whopping 8-9/10 even if art was somewhat flimsy.

Story 5/10

The story by itself is fantastic - drama(check), supernatural(check),seinen(check),shounen(sadly a check here too).
Originally it's a shounen manga but while it contained and contains naivety it's started out as mysterious dark and grimm (would not expect from shounen), scenes of violence and etc. Some philosophical inducing questions are questions and are arisen. Development of the story goes on without the end, you just don't see it stopping for the reader idle moments are usually time skipped (time skips vary from days to centuries). There simply doesn't seem to be a place for filler chapters.
While i did see some inconsistency and plot holes but i didn't see any major flaws right up until capital Arc and so forth.

Story is about a being a sphere to be exact that with a touch of blood of a wolf awakens and turns in to that wolf with no memory no knowledge simply animalistic instincts with fast regeneration and thus this story begins...A supernatural being with the power to transform to dead creatures that it touches and ability to regenerate quite fast.
Story starts with full on drama and tragedy it hits you from the start but then after some time it's becoming more comedic more shounen like and after some time it suddenly becomes more shounen comedy supernatural with drama and tragedy being a background noise or at least after seeing serious and engaging notions it becomes comedy so any drama after that becomes a JOKE!

Art 7/10

It's good but well you see that from a far art is well made background looks gorgeous but when you have a close up for characters they seem more sketch like, generally speaking it is acceptable because there are many things happening in one panel (various action scenes that are detailed). Panel placement is up to standard but as for speech bubbles i didn't get confused much but lack of pointers of whose speaking was present (maybe due to scanlator i dunno)

Character 6/10

Characters are fun to see they seem like thought through at the start right till middle point......
Our Main here at the start is literally a newborn and watching it grow is amazing but at some point we might start to see authors inclination to make our hero stagnate or degrade even in later chapters (reason being maybe due to it being a shounen so editor might have restricted author).
Next up are our supporting cast they are all mostly teens or kids when we meet them at the start and we actually see them grow which is amazing to see but like i said modern day Arc simply destroyed a hell lot of things for this build up and suspension went up like puff instead of bang.
A lot of characteristics are shounen like with crazy, whimsical and naive personality but that a lot becomes more and more dominating as the story goes on characters becoming more and more childlike or at least for shounen age group auditorium.

Enjoyment 6/10

This was a nice train ride for me if i were to say destination from A to B was majestic but starting from B to C we may start to see more and more bumps and my enjoyment subsided more and more until i went from making it one of my favorite mangas to mediocre at best if it ended before modern day arc i would actually rate it better but still quality drop is a big let down it grades down little by little from the starting chapters from something fun to read to something painful to read.

Overall 6/10

All in all it's a good read.
I would advice, for now to stop reading it after chapter 115 even before that it was dropping quality but at least it ended on a bittersweet tone which would compliment how it started opposed what you would see until chapter 136 (and maybe so forth).
I think author gon an opportunity to be serialized and due to it being Shounen Magazine after each volume editor guided author to change course from more mature theme to more childish theme it's a saddening fact where you see your favorite heroes degrading little by little.
I hope that this arc will be regarded as a joke or that they will change course since it was a big let down for me seeing something great becoming ever more mudded with silly antics.