I have few issues with the story.
First issue is that the story is way too slow paced, almost no progress even after 66 chapters. Second issue is the MC himself… Author has given us a cool backstory about a man who was deemed one of the best assassins of not the best, cold hearted individual who had almost no emotions, yet as soon as he wakes up, he is instant more caring, feels love towards a little sister and over all has a positive personality, he shows care towards everyone he meets, he knows he requires power in order to survive but instead of getting stronger, he makes stupid decisions that almost kill him and lands him in the hospital on numerous occasions. He is spending more time with “friends” than studying new was to improve his strength, he could try and mix his old skills with chakra and enhance them if possible but so far we haven’t seen much of that. Anyway, author informed us that the story will take a darker turn but Idk how long we have to wait, considering it took 66 chapters just for MC to age by 2 years (he is 7 currently) it might take 100 more chapters just for academy graduation and another 200 before mc becomes jonin. Aside from those issues the story isn’t bad compared to the rest of the things in Webnovel. I’ll save it in my library and keep an eye on it but so far it’s too boring to read. I hope my review doesn’t discourage the author from writing but I had to be honest.
Ps. This is my personal opinion and someone else might see the story differently, if you are interested, I suggest you give it a try.