User blog comment:ShonenChicoBoy/Shonen's Regimen and Tonic: April 2015/@comment-136273-20150417110210/@comment-18812574-20150417141541

Yeah but still, just cause a character is detailed or there's a lot of text/detail in the powers section... doesn't disqualify them from being a Mary Sue. You can have a detailed article and still be a Sue. I think you're talking strictly on the power-level/OPness of a character now, but I'm going to repeat myself here: the level of power doesn't matter so long as there are challenges for the suspect Sue to face.

If you go and create a Level 900 Super Grandmaster Saiyan sort of character, you still need to build challenges for them. Whether that be weaknesses or internal conflict they have to face, or perhaps an opponent that forces them out of their comfort zone, or perhaps they are deficient in some area. Perfect in everything = Mary Sue. And I'm not just talking about "well he's infallible in Zanjutsu but has weak Hakuda." I mean a weakness within their particular specialization. Think about it. You can have more than one grandmaster in an art, and each grandmaster will be distinct (hopefully) and have a different "style" (for lack of better term) and focus. In that same vein, they will also have their own, specific weaknesses that perhaps another individual of the same skill level does not share. This helps to make things more natural, could lead to interesting dynamics (esp. in character interaction) and helps avoid Marysueitis. Characters need to fail sometimes, imo, even if you are the "god of -insert-skill-set-here." Otherwise: there is no suspense, and even if your character isn't "flat" per say they will still be boring.

And I have to disagree with you on the "fanfiction" vs. "RP" thing. Sues are bad in both cases. Doesn't matter if you are solo or writing with others, they are still bad. Very bad.