Writing Quality: I have nothing to say since my 'grammer' is not really good. Though in my opinion it's not really fluid to read it. Sometime, I need to stop to understand the meaning.
Stability of Updates: Not really care. Author has their own update, as long as it's stable, it's fine by me.
Story Development: It's only six chapters so far, so I meh. It's only a childhood, so unless it's something important, no one is bothered enough to go into full details.
Character Design: A bit unstable. A +100-years cruel and peerless old man still act like a child (embarrassed and such). Although Author has dealt with it by him wanting to act like his age, it's still not to the point of embarrassed (In my opinion, Surprise and the like is okay, but embarrassed. At least, make him calmer even though he want to act like a child). There are still a few others, but I will stop at this.
World Background: I won't say much with only 6 chapters. However, it's not really good to be honest. First of all, after the introduction of the new place, I still have no clue where he live. You don't need into detail immediately, but leaving one clue or another can give us a rough picture.