What is it about the Warrior?
In many forms of entertainment, physical strength, courage, and warrior-like honor are often traits people like to see in protagonist characters, and plots that involve physical combat are also common. In fact, physical conflict, whether it's between two people or between a team of heroes and a powerful villain or villains, has been a popular source of tales and myths since the dawn of time.
In many ways, a warrior character on a quest of some kind makes an attractive idea for a main character and narrative structure. Usually, warriors are bound by some kind of honor code. In many cultures these warrior codes are found, to ensure loyalty to the ruler and to prevent the warrior class from disrupting society or terrorizing the people. As part of this code of honor, ancient warriors were those who defended their kings, protected the weak, and went after criminals.
A warrior's focus on physical strength also makes them a good character type, because they can be seen improving their abilities over time. Internal psychology is more difficult to see, let alone to see change or improvement in. However, it's easy for entertainers to show off their warrior characters' new abilities after a bout of intense training, by showing them defeating opponents they couldn't defeat before. This concept is a common storyline in many anime episodes.
I also believe the warrior as character type is widely popular because these people display a strength regular people can only dream about. I can think, Clare from Claymore for example could take a sword through the chest and get back on her feet, and here I am practically crying if I hurt my toe. Whether you're into dancing, martial arts, sports, or fighting in entertainment, displays of physical prowess are awe-inspiring and draw people in.
The Woman Warrior
When women are warriors in entertainment, it's often of interest to the audience because it's a reversal of traditional gender roles. Many anime, as well as some TV shows, comics and video games, feature women warriors as a protagonist. The earliest in American media was probably Wonder Woman, who first appeared in comic books in the 1940's.
Female warriors are often of interest for psychological reasons too, they find they have to balance their feminine, motherly natures often with the violent situations they get into. Often in fiction, women warriors are fiercely protective mothers or motherly figures for younger characters.
Sometimes they are heavily sexual, looking like fetish objects instead of warriors, and the worst industry about this is probably comic books. Does "strong woman" have to always translate to "woman who will stab you, but has to be wearing 8-inch heels and a miniskirt to do so? I wish the entertainment industry knew better, but they more or less seem clueless about it. Even some characters I really like, such as Cat Woman, are still more fetishes/ fantasies than real people.
However, there is more than merely the sexiness potential for female warriors, in my opinion, they can be great because it takes more work for a woman to be as physically strong as a man, and therefore I think women warriors are that much more amazing.
Also, in fantasy settings, women warriors are fighting the status quo and rigid gender norms of the society they live in. Brienne of Tarth from Game of Thrones is an example. Women like that are activists, challenging a society that's full of women's oppression and sexist attitudes. It's one of the reasons I cheered on Utena of the anime series Revolutionary Girl: Utena. Utena is a girl who wears a boy's uniform and engages in fencing duels. She has the honor of a warrior, the grace, beauty, and compassion of a woman, and the skill to hold her own against the best of male challengers. To me, Utena embodies what woman warrior-hood is at it's finest.
Anime and Samurai Tradition
Anime is brimming with warriors. The shounen (boy's) style of anime in particular is full of them. This is probably because of Japan's proud, ancient warrior-hood traditions. Unique to them are the samurai, their ancient caste of warriors, famous for their code of honor and tradition of loyalty to their lords. Because samurai had the highest honor and prestige of any class in feudal Japanese society, besides the aristocrats and emperors, they had a heavy influence on the development of Japanese culture.
I also believe that Japan has always been a fragile nation, with volcanic and seismic activity, tropical storms, and many attempted invasions from the mainland. This is why I feel that Japan has such a culture that strongly focuses on warriors, warriors are protectors that their country looks to in troubled times.
Knights in European Legend and Fantasy Fiction
Much has been written about European knights. Like samurai, knights had a tremendous impact on the culture they inhabited. Probably the most famous knights of legend are King Arthur's knights of the round table. Like samurai, knights fought wars in the service of feudal lords and kings, and were expected to behave loyally and honorably, according to a code of conduct. Originally knights were mounted warriors, but in modern times knighthood is simply an honorific title that a king or queen can bestow on anyone. In most instances, knighthood was a hereditary title. In addition, even early on there have always been a few female knights in England, France, and Italy (wikipedia). Although she wasn't born a knight but rather a peasant, St. Joan of Arc is probably the most famous female warrior from medieval European history. Joan of Arc was inspiring military leader who seemed to have an incredible effect on the morale of her troops. Real, historical heroes like her have inspired numerous fictional heroes.
The European traditions associated with knighthood have had a tremendous impact on modern fiction, especially the fantasy genre. Fantasy novels often follow a "hero's journey" plot style, and the hero involved is usually a knight. Tales of knights rescuing women and slaying monsters have been common in European folklore for centuries. The idea has become so cliche, in fact, that modern writers usually have to come up with a twist or turn to make the idea interesting. For example, the Last Unicorn, in which the "damsel" is really a unicorn in human form, who actually abhors violence even against monstrous animals, so that the "knight in shining armor" seems helpless when it comes to wooing her!
Warriors of the Ancient World
Ancient legends of warriors, and historical battles, are often the inspirations for modern fiction. One example is the movie 300, inspired by a historical battle between Greek soldiers and Persian invaders. We get the term "marathon" from a historical battle, and the "Trojan horse" comes from a mythological one. Ancient civilizations were enmeshed in a lot of bloodshed and turmoil. Greek city-states, and many other small kingdoms and city-states, dealt with threats of conquest by large empires. Today, the Roman empire, with it's cultural focus on masculinity, expansion, and conquest, also influenced many fictional depictions of warriors today. Whether they showcase the ferocity of the Romans on the battlefield or the harshness with which they treated enemies, slaves and gladiators, stories about Roman warriors seem to often captivate audiences. They were possibly the earliest European civilization to glorify the warrior class above others, coining the term "miles gloriosus", or glorious soldier, who was held up as an example of manly virtues.
Many modern super-heroes have Greek or Roman roots. Wonder Woman is a princess from the Amazons, a society of female warriors from Greek myths. Many warriors in fiction have Roman-style armor, possibly because it was beautifully decorated in addition to being functional (although later, medieval armor was stronger). Bronze-age weapons are often a part of the set of possible weapons in the Soul Calibur series of fighting games.
Ancient Warriors: China and other Asian Cultures
Martial arts, ancient styles of hand-to-hand combat originating primarily in Asia, are also the basis for many TV shows, movies, anime, manga, games, etc. Ancient warriors in China and other far-eastern countries that were primarily Buddhist have always been known for their skill worldwide. I believe that Buddhism and meditation go hand in hand with that, as ancient warriors were able to apply Buddhist teachings to the battlefield. Martial artists make good characters because, while they are skilled at violence, to them, fighting is an elegant art form, like a dance. They also tend to be virtuous and have high degrees of loyalty to their dojo, mentors, and comrades in arms. Martial artists, like samurai, figure greatly into anime. Many of them are warrior-monks with a high degree of spirituality, others are simply killers. Usually, however, the cold-blooded mercenary type of martial artist is the villain, and the good characters have loyalty to their friends, sophisticated manners, and respect to all fellow warriors, even opponents.
American entertainment often creates Amercian heroes that represent the strengths of the American military, while British heroes like 007 emphasize Britain's dominance in the field of espionage. Modern warriors represent the best champions for their countries, and as champions represent the strengths and virtues associated with those countries. Many superheroes, such as Captain America, are good examples of this.
In particular, I feel like comic books and movies inspired by them are all about American bravery overcoming modern threats to American security, such as terrorism. Many comic book villains have similarities to real-world dictators, terrorists, or other threats to American peace. In many of these stories, iconic American places are threatened by the villain, such as New York City or Washington D.C. The warrior heroes show the audience that America will always win, even if the odds are against us and our cities become a battlefield. Although war has never broken out on U.S. continental soil since the Civil War, it seems that these movies point to a looming fear Americans have of war coming to their back yard. However, in some modern Japanese war animes and movies, American and Western imperialism is the threat to peace, such as in Code Geass.
Modern warriors are popular as characters because modern weapons are cool and powerful, and because the story relates to what's really happening in the world. For example, Tony Stark in the Iron Man movies is a modern hero, but a reluctant one, representing the conflict between greed and the inherent selfishness of capitalism and the needs of the many presented by invasion or terrorist threats.
Problems With Warrior Characters
Even though warrior characters are used because they can be glorious, inspiring, and righteous, there are a few issues that come up when writing a warrior-based story.
For starters, when is the killing of another human being justified, and when is it 'murder'? The anime Claymore explores this question in an interesting way; warriors in Claymore are forbidden to kill people. But one Claymore rebels against this rule by killing a band of brigands and saving a little girl. For this crime, however, she is still punished with a death sentence. The organization doesn't want humans to fear their warriors known as "claymores", and so the rule against claymores killing humans must always be strictly enforced, regardless of the circumstance. I feel that any good warrior story should have the protagonist grappling with the issue of killing another human being.
This brings up the question of morality. Is there truly a such thing as good and evil? Who knows if 300, told from the perspective of the Persians, wouldn't be able to make them look like the 'good' guys? Maybe morality is just in the eye of the doer. In many stories, the protagonists are "right" and "good" because the story says they are, and not much time is spent questioning that fact. However, having a character that is defined as a fighter and killer presents this interesting dilemma. To quote Rurouni Kenshin, "A sword is a weapon. The art of swordsmanship is that of learning how to kill." Pretending killing is morally correct in every instance is not something Rurouni Kenshin does, and I like that the show deeply explores the psychology and ethics associated with warrior-hood.
"War is hell" is another thing that can make warrior stories a challenge. Game of Thrones (and the book series the show is based on, A Song of Ice and Fire) in particular pulls no punches when it comes to describing just how terrible combat really is, and that's one great thing about it. In addition to being messy and tough, genuine historical and modern soldiers often have no choice about which side they end up on, and Game of Thrones in particular shows how often good people ended up being bound by "knightly honor" to do all sorts of unpleasant things and support unpleasant lords, kings, and queens. When a lord declares war, knights and soldiers under that lord's command must go to war, and that is what knighthood or warrior-hood meant in the old days. And cute maidens in towers? Real knights had either prostitutes or women they raped when invading a town, in addition to many of them having arranged marriages for political reasons.
In modern fiction, authors are becoming more bold about exposing the ways real knighthood was anything but shining. But we still have this image in our heads of knights that doesn't mesh with historical accuracy, and an author must choose between the two. I imagine this goes for other types of warriors mentioned here, as well. I mean, ancient Chinese and Japanese warriors did more than practice calligraphy and contemplate flowers. A samurai in particular was also bound to commit ritual suicide, or seppuku, in cases where they committed an offense to their family's honor or if defeat in battle seemed inevitable. In modern times, we have named and begun researching Post Traumatic Stress Disorder or PSTD. However, prior to the Vietnam War, PTSD was just called "shell shock" and soldiers were expected to just "get over it" because men weren't supposed to show weakness by being psychologically vulnerable. However, the truth is that many warriors end up doing or seeing things on the battlefield that haunt them for many years afterwards.
What it boils down to is, when writing a story involving fictional warriors, how much realism do you want to go for?