For my BW fic, I intend to write Hilda as a 14 year old girl who's a true protege at Pokemon training and can really kick ass without a Pokemon. Before the series began, she would rigorously train with her mother's help to always be strong and physically fit so when out in Unova, she can take care of herself. She's an outdoorsy tomboy who would go to the forest to camp out or even train to be a real survivalist in case she gets lost as a Trainer. She loves Pokemon and can even communicate with them (in contrast with N as shown in the story), making a few forest friends she often plays with. She does have friends like Cheren and Bianca and also enjoys other stuff people normally do. She can be playful and childish when in a good mood but when the situation calls for it like when dealing with Team Plasma or in any other battle, she become a serious and strategic contender who thinks quick and holds nothing back. She's nicknamed The Battle Maiden because of this and her birth name having the exact meaning. She's also an explorer whose curiosity often lands her in trouble but she manages to get out which she considers part of the fun. She's also sweet and compassionate and prone to hugging the hell out of anything cute (just ask her Oshawott). Of course, she's not infallible and can make a few mistakes and oversights here and there. Her heroic nature makes her reckless like when she actually goes to get her Oshawott back from Team Plasma mostly with a Pidove she caught on her own (she already knew it personally though) and her own manpower but her wits allowed her to succeed in saving her starter.
Now I'm quite confident in this character. I won't self-proclaim that she's "great" but I'm sure that readers with not at all see her as a Mary Sue as far as I'm concerned since she'll have a tough time getting to the top. But, my characters aside, it makes me wonder about the fine line between an "amazing, well-rounded, badass" character and a "dull, perfect, contrived" Mary Sue. I've gone around hearing "they gotta have flaws or else they're a Sue" and such that I was once afraid that my protagonist would be ripped apart due to all of the above. But I'm now confident that if I give her a shot, things might not be (so) bad. All the same, I have to ask about this difference I've come to be aware of.