What's a Gary Stu?
Notes on appearance:
1. He is ruggedly handsome.
His body is almost always very muscular, much like a bodybuilder, and he makes it obvious that this is not just for show. He is tall, strong, and very much the epitome of masculinity.
2. His hair and eye color, while not stressed upon excessively, will get described in detail at least once.
Due to his manliness, hair is - more often than not - short, but thick and stylish. Adjectives are used sparingly to describe it; usually, they include less flowery things like "dark," "light," "wavy," "straight," "thick," and "short," or "long," if they are present at all. He has blond, brown, or black hair, though sometimes a stranger color like red or silver. Sometimes, he may have long hair. This is due to a desire to be Fabio-attractive, or to having a female author writing the story.
His eyes are less described. Their color will creep into the story at some point. His eyes can be brown, blue, green, gray, or any other odd color of the rainbow, yet they must always be capable of capturing interest or striking fear into his enemies' hearts.
His skin is very rarely pale. Paleness to a Stu indicates weakness, unless he's the silver- or red-haired type, which are exceptions to the rule. Gary Stu is tanned, to go nicely with his muscles. In most cases, there are few adjectives except for just that: "tanned." Being too flowery with adjectives is so clearly not manly. However, a female author may forget and bend the rule.
3. Gary Stu, like his sister, can have markings of some kind, typically relating to his past. These can be scars, tattoos, brands, or some kind of "body paint" - never makeup - but they, again like his sister, are almost always relevant.
If not relevant, they are present solely to make him cool, attractive, or visually interesting.
4. Non-human Stus - everything from vampires to lycanthropes to youkai to the rare angel - must have evidence thereof, lest anyone dare mistake them for a mere mortal.
Youkai or hanyou Stus, like their Sue counterparts, have animal ears, a tail, claws, catlike pupils, and/or fangs, or any other animalistic feature. This can include the obscene.
Eye color changes in the case of a non-human race, usually arousing suspicion amongst other characters. It can be red, gold, or silver, or another color that is considered strange.
Any wings he may have are not pure and white. They are more likely black, or perhaps a dark - almost black - color.
Notes on background:
1. He has ties to a favored canon character.
He is a relative, a friend, a coworker, or even a rival.
2. He has some connection to a canon character's past.
He can be a former lover, or at least someone whom the character considered attractive, or a mere friend (though usually he will become more). He may also bear a grudge against the character, be it legitimate or not. He believes his opinion to be right, which is why he will not forgive the character easily if this is the case.
If he has been reincarnated into his current body, Gary Stu can re-meet a character from his past life, causing much confusion and angst.
3. He is a new transfer student (if in a school setting), or a new employee.
He is from America, Canada, Britain, or Japan, depending upon his destination. The former three arrive in anime situations, and all but Britain may arrive in fandoms such as Harry Potter.
4. He appears out of nowhere.
He behaves like he is a canon character himself, or at least attempts to. The canon characters are already his friends or love interests, and also pretend that he is part of their universe.
Notes on personality:
1. He is cold and brooding.
He makes sarcastic remarks, even to those characters he counts as friends, and there are not many, if any at all.
He is downright rude to characters whom the author dislikes or considers "sissy/weak."
At the worst, and most provoked, he will physically attack other characters. Not the females, unless they display immense strength; this honor is more often than not awarded to males seen as either very strong or very weak in canon.
He may - operative word being "may" - be reformed, though never entirely cured of his cruelty.
2. He is an emotionless, expressionless warrior.
His past may have something to do with this. It is often a painful past, one that made him believe that he cannot trust anyone.
Though he may fall in love with a canon character, he finds displaying feelings hard, and this can strain the relationship.
3. He has bordering-on-clinical depression and is pessimistic.
Upon falling in love with a canon character, he realizes that the world can be a better place, and that depression is hurting him.
Instead of depression, he may have a would-be version of bipolar disorder, causing him to have brief spurts of happiness or sociability before he pulls away into sadness again.
Notes on abilities:
1. He has unbelievable physical strength.
His muscles must make this very evident, giving him a clear advantage over his foes.
In some stories, it may be mentioned that he can kill an enemy with his bare hands.
2. To accompany his strength, or to surpass it, he can have supernatural powers.
He may display telekinesis, telepathy, and other psychic abilities. (Not empathy, though, as this is usually an area in which females excel.)
His ki is powerful and he can attack with it to the point of obliterating his target.*
3. His speed is amazing. He may move as a blur, no matter how much armor he has on, the weapons he is carrying, or what kind of cumbersome clothes he is wearing.
4. The canon characters are all weaker than he is, or at least have lesser skills.
5. He is able to beat any enemy, even those that the canon characters can/could not.
Notes on story plot:
1. He is the only one able to save the world from imminent danger.
Canon characters' abilities often do not figure into this equation, and they must watch in awe as Gary Stu does their job.
2. He falls in love (unnaturally quickly) with a canon character.
While not usually the entire plot, this provides plenty of filler material when Gary Stu is not saving the world or fighting his enemies. It also provides opportunities for sex scenes.
3. Gary Stu appears and becomes a member of the cast in some inexplicable way. These scenarios often lack plot almost entirely.
Canon characters behave as if Stu is also a canon character, despite the strange things that happen in his wake.
4. Somehow, he is introduced as a family member of a canon character, allowing him to jump in on the action that centers around them.
He is usually someone's brother, leaving all opportunities open for him to get the girl.