User blog comment:Varzan Deodinm Beldinm/How Much Canon-Fanon Interaction is too Much?/@comment-24087318-20140110030151

Words From An Admins Mouth:

When it comes to the concept of Character Acception/Rejection, which is a part of the Fanon in that only Accepted characters are allowed to Roleplay on the site, Fanon-Canon interaction in your characters Profile CANNOT Involve Canon characters, events, or major organizations barring the following:

-Professor Ozpin, Given some peoples profiles involve them being admitted into Beacon under special cases due to their skill or ability, like Ruby, he is allowed to be included.

-Beacon Academy (And other Hunter/Huntress academies) Since...it's pretty likely your character will be going here.

-What's In The News, your character may HEAR things like Roman Torchwick being on the loose and wanted, and the increased crime rate involving Dust shops (with the rumors that the White Fang may be behind them) But likely won't be involved in these events. (Didn't see Ruby/Glynda first encounter them, or Blake discovering the White Fang are with Roman)

Again, these ONLY apply to Original Characters, or things connected to them, when they're going to be Submitted for Reviewal. Fanfics are anything goes.

Concerning your specific questions and exmaples, they both break the above rules if you are trying to have your character listed as Accepted on the Fanon, and WILL be Rejected due to them. It gives Blake an opponent if your character is going to Beacon alongside her, and directly involves Adam as a character, as well as guesses his exact rank and file among the White Fang, or if he's even still a member.

And, as for wether or not your character would be flagged for Mary-Sue/Gary-Stu levels, that's a matter of opinion, not so much fact.