Dean Winchester was trained as a hunter by his father, John, to save people from evil supernatural threats. However, unlike his father, he is not as fixated as Ahab on the Great White and has learned to give even preternatural people the benefit of the doubt. His family has a reputation, and how they're seen will depend on who is asked. But in general, Dean tries to do the right thing, though he can be volatile if his family or friends are endangered.
Personality
Dean Winchester is a charming, outgoing type that tends to give a positive impression of himself. He's plain-spoken, simple in a number of ways, and typically unpretentious in most things. However, those who know him over a period of time can find him annoying, overbearing, and childish, as well as overextending aspects of his personality to cover up serious emotional damage he has found difficult to deal with; in attempting to be a dudely dude over the years, he's bought into the compulsion to push emotions aside and neglect feelings, but he's also found that increasingly difficult as he grows older. Dean can be surprisingly complex, though most people he deals with don't get the opportunity to know him for very long since he's in and out of lives in the time it takes him to resolve whatever preternatural threat he's needed to resolve. He's the kind of person who easily integrates himself into most situations as if he's an old friend, but he keeps everyone at arm's length and is gone before anyone can probe deeper.
Background
Dean Winchester was the first born child of John and Mary Winchester, who had been secret fighters against supernatural threats before settling down to raise a family together. Things were fairly quiet for some time, and Dean later welcomed a younger brother, Sam. Unfortunately, when Sam was still very young, his mother was attacked and murdered by a figure the Winchesters only could know as "the yellow-eyed demon". John and his sons escaped with their lives, but it meant that Dean was essentially drafted into a life he never asked for and never wanted, of endless motel rooms and a far greater responsibility for his brother Sam than ever before.
While John traveled around with a fire lit in his chest to prevent the tragedy of his family from happening to others, he ironically made things very difficult for Dean and Sam. Dean had to learn early on how to deceive, how to steal, how to handle weapons and kill if necessary. It was not a glamorous or particularly fulfilling life. When Sam walked out on them to attend college, Dean was devastated but at the same time couldn't fault his brother. Then their father vanished, leaving few clues other than his journal. Dean's only option, he decided, was to find Sam and recruit him to find John together.
Unfortunately, their reunion came with a tragic cost, leaving Sam's life in ruins and Dean even more convinced that they needed to find their father. On the way, the brothers learned what their own approach would be to the life their father left them in fighting supernatural threats, and overall they adopted a fair and more reasonable, less fanatical attitude. Nonetheless, the two clashed in a number of ways and also had to learn how to relate to each other. When they did find their father, they discovered he was on the trail of the yellow-eyed demon and more than slightly blinded by the narrow focus. John and the boys parted ways again, but with the resolve that the tragedy from their childhood would, some day soon, come to a final confrontation.
SKILLS
BRAWLING: Competent - Dean is highly experienced in knock-down, drag-out brawling. He can hold his own in a fight. There may not be much finesse to his fighting style, but he's at least able to give as good as he gets most of the time.
CHARISMA: Expert - Dean is charming to most, which can be quite an accomplishment considering his personality. He's highly persuasive, able to make people do what he wants through charm, as well as encourage people to agree with what he's saying...which in some cases is a miracle, since many of those he has to persuade are, at the time, of the mindset that the supernatural does not exist. He can also deceive others easily, effortlessly even, and is able to maintain a deception for some length of time. Furthermore, these abilities also assist him with undermining the authority of others and winning people over to his side, and other subterfuge of all kinds.
FOOD: Novice - Dean is great at eating! But more than that, he's an able cook. Maybe not the best ever, but he knows his way around a kitchen and can put together a well-prepared and sufficiently nutritious meal with minimal fuss. He is also able to appreciate food, though his tastes are not the most refined.
INVESTIGATION: Competent - Dean is surprisingly good at investigation, putting clues and evidence together to figure out what happened or what's going on. While he's not the best at using all of the technology and resources at his disposal, he manages as best he can when necessary. Dean is good at noticing things others might not, putting together things that others might miss, and generally a fairly good detective.
LORE: Competent - Due to his training during his youth, Dean is familiar with a wide range of supernatural lore. Although some may be apocryphal, there's a great deal that is accurate and which he has, additionally, experienced firsthand. What he doesn't know offhand, he stands a good chance of being able to find out or extrapolate from context.
MECHANIC: Expert - Dean is intimately familiar with the workings of automobiles, especially the older ones that are easier to work on, without all the complicated computer systems everywhere. He keeps the Impala maintained and can also work on other automobiles if needed. He has a grasp on how the systems work to a high level and could work on the level of a professional.
SURVIVAL: Expert - Throughout his life, Dean has had to learn to survive in the face of overwhelming opposition. From when he was very young, Dean was taught to scrape through a terrible situation; any disaster you can walk away from is a victory of some kind, and when Dean had to look after his little brother Sam, his responsibility increased. Because of this, he is generally able to find a way to get through, if possible, even when most everyone else gives up.
WEAPONRY: Competent - Having been trained to use a variety of weapons by his father, as well as practical experience using weapons alone, Dean is proficient with firearms, bladed weapons, blunt weapons, and to a lesser extent knows his way in a basic sense around a number of other weapons such as bows and polearms. He has the foundation, so it's not difficult for him to adapt to new weaponry fairly quickly and be generally assured of being able to use it at least decently well.
ABILITIES
ADVANTAGES
ARSENAL - In the trunk of the Impala, Dean keeps an arsenal of weapons and handy items that can be used against any number of foes who might stand against them. Guns, stakes, salt, lighter fluid, and even more obscure and rare items can be found here and are kept safe with a special lock.
CASTIEL - Dean has a personal link to Heaven and the Powers That Be, by way of Castiel...his guardian angel of sorts. Although their relationship had a rocky start, they have become much closer since and Dean has accepted both Castiel and the forces he represents. He can be great help in a tight spot, and his advice and guidance have helped the Winchesters and those they seek to protect out of a number of tough situations, to say nothing of his superhuman abilities.
IMPALA - Dean is the very proud owner of a 1967 Impala, which is his pride and joy. It's in extremely good repair and is well-maintained by Dean, as well as kept clean insistently...or some might say, obsessively.
JOURNAL - Filled with John Winchester's experiences, battles, and information he discovered, the journal is an invaluable resource to those in need of data regarding the supernatural. Naturally, it's limited by his personal experiences, but it still contains information from practical experience that is rarely assembled in one place.
WILLPOWER - Dean possesses stronger willpower than the average. It is much more difficult to influence him, even under duress, and he is able to comprehend, or at least endure, things beyond the typical human experience without any serious detriment. He has successfully pushed through numerous situations that would cause others simply to break.
WEAKNESSES
ADAM - Adam Milligan, to Dean, is still his brother and still his responsibility. Even though he didn't grow up with Adam, or even knowing about their father's other son, Dean instantly took to him after meeting him. As the oldest brother, Dean feels the greatest responsibility to Adam, not only to protect him from danger, but also to do whatever is necessary to keep him safe. As with Sam, Dean is often highly parental and protective, even to the point of being a little overbearing. There is very little that Dean would not do for Adam, and he can become irrational, unreasonable, and rash when Adam is put into danger, especially if it is because of Dean.
BIAS - Dean can be more than a little biased against some supernatural entities and may be at a disadvantage against them, or even in a situation where he is required to help them. He can learn, of course, and he knows that not everything is evil just because it has a superhuman gift or curse, but due to personal experiences, he's still highly uncomfortable around certain types of beings.
BROTHER - Dean and his brother are remarkably, profoundly connected. It could even be said, and accurately, that they are dependent upon each other. If one is threatened, the other one will go out of his way to save him. If one is harmed, the result from the other may be violent and irrational. Reason is cast aside where Sam is concerned. Dean will stop at nothing to save his brother, to protect him, to ensure his safety, including putting his own life in danger...ironic, since Sam is much the same with regards to Dean. "There ain't no me if there ain't no you" sums up their relationship in brief. Dean would stop at nothing, sacrifice anything, and pay any price to save his brother. Any of their enemies who are aware of this could exploit it, as it is accurate to say that Sam is Dean's greatest and surest weakness.
DAMAGED - As much as he would like to gloss over it and pretend he's perfectly well-adjusted, Dean is the product of profound childhood trauma and an extremely unhealthy upbringing. He plays it off most of the time, but anyone who gets to know him longer and better will start to notice the cracks in his armor of easy flirting, adult entertainment, and drinking. Dean is desperate for approval, has a vast array of issues with his father and his brother, and tends to maintain a bleak outlook most of the time.
LOWBROW - Dean is, for lack of a better word, a dude type. He fits into a number of stereotypical behaviors. He can be so butch at times that it really seems he's overcompensating. While he's often a charmer, he can also be sexist and his charm can't always brush that under the rug. He can be condescending, and he has been known to try and abuse his older brother status, though rarely with any real success. He isn't very refined or sophisticated, and it can be difficult for him to even pretend convincingly. He is decidedly out of his element in higher-class surroundings.