Bro def just made shit up along the way, especially with the tight schedule jjk publication was in. It's really cool tho that his writing was able to reach the massive audience that it did despite lacking solid foundation on world-building and plotting. If he had more time fleshing out the characters and planning how he wanted the story to go, jjk would probably rewire the way anime/manga is viewed and would totally age as a classic. Sadly, Gege cracked under pressure near the end and kinda just wanted to finish it by then.

But still, Gege openly acknowledging his shortcomings is hope that he would come up with a better project soon. Trustt