Thaddeus Howze is a professional writer mainly in the Science-Fiction genre, see his website - Hub City Blues, read his own bio on Medium and check out his author's bio on Amazon.
He may not have directly asked/answered questions on his own canon, but he is an active professional on this site.
Recently, user SQB asked the question: Who are the architects ...
Eliezer Yudkowsky, author of the famous Harry Potter fan fiction Methods of Rationality, contributed an answer to a question about his work.
Another (unregistered) user had previously used the name "Eliezer Yudkowsky" to answer a MOR question.
I'm not a moderator here, but I see no problem with this.
This user sees him or herself as an expert on a specific topic relevant to our site. They've posted numerous answers that seem comprehensive and knowledgeable (at least on the surface; I haven't had a chance to read them in detail yet, and I likely don't know enough about Superman to accurately judge ...
Let's look at their profile.
Nothing wrong here. That's exactly what the field is for.
Welcome to the ManOfSteelAnswers.com where we endeavor to answer the questions, criticisms, and controversies raised by the 2013 film for Man of Steel fans and those excited by the anticipated DC Cinematic Universe. [snip]
Elio Miguel Garcia Jr
The co-author of the book The World of Ice and Fire and renown A Song of Ice and Fire 'superfan' and collaborator with George R. R. Martin, has made a couple of appearances on this site.
His answer to What is the in-universe title of Yandel's ‘A World of Ice and Fire’?.
His answer to Which bastards in ...
The following question:
What's going on legally between CBS/Paramount and Axanar and how does it relate to Star Trek: Discovery (if at all)?
attracted an answer from Sai, founder and former president of the Language Creation Society and the LCS's official spokesperson in the case.
Not only is this an answer from someone professionally involved in the ...
Assuming we focus purely on questions answered by word-of-god authorities where that question was prompted by a question asked on SFF:SE, then there are plenty to choose from.
Question About Fantasy Novels By F.J. Hale/Robert E. Vardeman - Robert E. Vardeman
Do they have surnames in Stonewylde? - Kit Berry
What exactly *were* the ...
Franc Ross, who portrayed Monty on Firefly seems to have answered my question about the character.
Is Monty's last name actually Reynolds?
Leland Chee also responded to a Tweet I asked to answer this question:
Why is the planet Lola Sayu so damaged?
I've just checked it (by clicking the link) and it doesn't appear to be working.
Also, can we please get an official SFF:SE MySpace page and a Second Life page as well? I'd hate to think we were missing out on the social network revolution.
This question makes a good, clearly-explained point about the plot of The Winter Soldier, and gets a detailed answer that I think explains it:
What is the Lemurian Star really doing in Captain America: The Winter Soldier?
And I think this one asking about all of Stan Lee’s cameos is pretty fun, with decently-sourced answers (they got the word of The Watcher! I mean God!):
Is Stan Lee playing the Watcher in all his cameos?
It seems that Madeleine Robins answered a question on one of her books here:
Is there a reference in the first line of Madeleine Robins' "Petty Treason"?
Chuck Jones apparently answered a question about a model that he designed for a Half-Life character:
How did Gordon Freeman survive the entire storyline without a helmet?
The person who created the Toby the Targ stuffed animal prop answered a question about whether they're available anymore, at Does a stuffed 'Toby the Targ' toy exist?.
Matthew Hughes also answered a question about a short story of his. After a bit of confusion where his answer was deleted for not answering the question, it was all sorted out and his ...