D.Grayman: Initial differences and similarities with the world used in this fan-fiction include-

Differences

The 14th will not be reincarnated into Mike’s body since how he got his memories implanted in Allen Walker is a bit confusing. There's a whole explanation on how the 14th met Allen 35 years before the current events of the original work, but it's confusing whether or not Allen is that old or somehow traveled back in time. Mike will be born within how old Allen was thought to be in the original time line. Also, the 14th won't reincarnate into anyone at all, since no one bothered to save him. We'll go with him being absorbed by Mana and then they formed the Millennium Earl. (B: There were a lot of things that confused both of us about the whole 14th mystery, so since the world is only similar, we decided to go with what we found online and just have the 14th disappear.) There will be new characters introduced since it'd be unlikely that Mike would meet the original characters until maybe later in the arc. Mike will not be called Allen Walker since he sort of got that name from Mana Walker (adoptive father) Mike will see the Black Order people as nice people but will ultimately still only truly cate about a select few

Similarities

Noahs, the Earl, and the Black order will stay the same except for the added/changed characters. Major characters of the groups still be the same. Basic plot of the story remains the same (Noah + Earl + Akuma vs. Black Order + In a way the Bookman) Everything else should stay the same/similar (keep in mind that this story is in development so there might be more differences)

Major Characters to appear

Klaud Nine: General of the Black Order

Lenalee: Exorcist and side character. She wields a type of boots innocence.

Lavi: An apprentice bookman who wields a hammer innocence.

Road: Noah who controls dimensions/dreams. Like Noah, she controls dark matter and commands akuma.

Tykki: Noah who controls physics.

Lulu: Noah who can shapeshift.

Earl: The antagonist.

More may be added.

Remember, this world was intended to be similar, not a replica. Also, I may watch anime and read manga but I don't spend my time remembering all the little details. I had to search online for this(I had to type in what A wanted to search since he spent an hour looking through the Internet without finding the right info. A is just not meant for research.)

Google if you don't know something, this is a fanfiction, I can't explain everything.