Raven

Raven was introduced in Tekken 5, and he returned to Tekken 6.
Raven's ninjutsu fighting style is highlighted with his teleportation moves and extremely quick maneuvers. He is highly similar to Kunimitsu, a female character who has not made a canonical appearance since Tekken 2. They do not have similar moves, but their techniques are similar (previously described).
To date, despite not being of Japanese origin, Raven is actually the most traditional (and some would say even lightly accurate) ninja in the Tekken series. His fighting style, a combination of grappling, take-downs, and heavy strikes has light inspirations from supposedly real hand to hand combat ideologies practiced by the Ninja. By no means perfectly accurate, it is however more accurate than the typical multi-hitting speed demon style often used by ninjas in video games, as real Ninja often opted for quick take downs and grapples to incapacitate. Many of Raven's other qualities are much more traditionally Ninja (as depicted in fiction at least) like than that of Yoshimitsu, such as his tendency to leave a scene by jumping into the air, his hand symbols, and his poses. Raven's second player outfit is very traditional Ninja attire complete with a flowing scarf, light armor, hood, and a cowl.
On a humorous note, when Yoshimitsu fights Raven in Story Mode, Raven cannot believe that Yoshimitsu is a ninja, as his fighting style and colorful, as well as deceptively clumsy, style is supremely unlike that of a ninja (it can be argued too that Yoshimitsu is quite far away from the archetypes of a ninja despite being one by profession). Raven, in a rare showing of personal agenda, eagerly takes on Yoshimitsu to show him true Ninja fighting. If Yoshimitsu loses, Raven will attempt to teach Yoshimitsu how to perform the kuji-in (a long time Ninja trait in fiction) with humorous results as Yoshimitsu has difficulty doing it. This is a lighthearted moment for the rather stoic Raven.
Raven bears some similarities to Wesley Snipes. He takes characteristics from some of the characters he has played in films (Simon Phoenix's hair, Blade's style and similar clothing, etc.). However, when asked if the similarities were intentional, Namco stated that it was purely coincidental. Raven has enjoyed a warm reception for his unique fighting style, and for the fact that he's a rarely seen ethnicity (an Afro-Canadian) when it comes to ninjutsu. He is considered a low tier character, as Raven has to take unneeded risks to do decent damage to an opponent.
Whatever costume Raven wears (with the exception of his extra costume ([1]) / ([2])), he always has two kunai strapped to his waist. Curiously, he never uses them in any of his moves despite his rather cinematic use of them during Tekken 5's intro movie making short work of a Jack-4 unit. Another rather interesting thing to note is that the name "Raven", obviously lifted from the bird itself, is a reference to the Japanese demon Tengu. Sometimes, Ravens in general are called Tengu, as well. What makes this interesting is that in Japanese mythology, as well as history, Ninja were sometimes called Tengu due to their dark outfits and covert ways. Some Japanese myths incorporating anthropomorphic animals, such as Tanuki and Kitsune, often depicted Tengu (anthropomorphic Ravens along similar lines to Tanuki) as ninjas. This is, in fact, one of the most ancient archetypes of the Ninja.
Raven is a stoic man, with a quick intellect and unbreakable sense of professionalism. He takes pride in his job and status as a Ninja. Although the nature of his company is ambiguous, his actions imply it works towards the greater good. He finds it difficult to believe in the more supernatural elements of his missions, but when faced with them, he takes it into his stride and doesn't lose face. His seriousness is a constant trait of this character, only broken if Yoshimitsu loses to him in his story stage. Baffled by Yoshimitsu's bizarre attire and clumsy ways, he attempts to teach Yoshimitsu the kuji-in, and grows uncharacteristically frustrated when the other fighter fails to so. His rivalry with Sergei Dragunov seems to go deeper than mere professional interaction. If one faces Sergei Dragunov in Scenario Campaign (in a rare show of speech) the other agent threatens to carve more scars into his face. This could imply that Dragunov was the one to scar him. Interestingly, one of the only times Dragunov speaks openly is to his rival, Raven. An obvious history exists between them.