You can tame a dog with food... you can tame a man with money... but no one can tame Mibu's Wolf.
From: Rurouni Kenshin (Nobuhiro Watsuki)
Ah, definitely one of my favorite characters of all-time. He reminds me very much of Dirty Harry, except with a slight supernatural overtone and a chilling demeanor that is more reminiscent of Jack Nicholson in "The Shining". He's a more mature version of the typical tortured soul. Experience and reflection have made him aware of his internal conflict and the pain that it can cause, so he's dealing with it. Most characters are either unaware of their personal problems or they avoid facing their demons.
Based loosely on a real veteran of the Bakumatsu no Douran (series of Civil Wars that ended the Tokugawa Shogunate), Saitoh Hajime was the captain of the Third Squadron of the Shinsen-gumi, sworn protectors of the old government. In the story, Saitoh is a fearsome and widely-respected warrior who believes strongly in the code of the Shinsen-gumi to destroy evil in all its guises. In flashback, his brilliant leadership and tenacious nature are displayed in the struggle against the Ishin-shishi revolutionaries. Moreover, he develops a grudging respect for his most skilled enemy, Hitokiri Battousai (aka. Himura Kenshin) the best warrior-assassin of the Ishin.
With the dawn of a new order, the Meiji era, Saitoh's myriad skills are put to use in an administrative position, but the arrangement leaves the former warrior in a quandary. Saitoh's problem is fairly common in his day. He finds that he is an expertly skilled warrior and tactician who has sworn his life to the fight against evil and injustice.
However, political and economic maneuvering often requires despicable methods in order to change people's lives for the better. While killing among the populace is punished severely, madmen with delusions of grandeur menace and murder with impunity. As head of the newly-formed federal investigation bureau (spies), Saitoh must balance his desire for vengeful wrath with the political reality of the new Meiji state.
Although he's more like Secret Service than FBI, he reminds me of Asst. Dir. Skinner and Cancerman (aka. the Cigarette-Smoking man) on "The X-Files" in that he has a job to do, but he obviously has a private agenda to carry out. When that job conflicts with his duty or with his conscience, that's when the story gets interesting.
Some folks might say that Saitoh doesn't have a conscience, because he's willing to use manipulation, torture and murder to achieve his ends. I don't hold with that, because there have been several scenes where he's tried to prevent someone from being hurt physically or emotionally. The most notable example is his grudging mentorship of Sagara Sanosuke, which gets more attention in fanfiction than in the series. Unlike many other anime characters, Saitoh is shown as strong and helpful without being afflicted with a major personality flaw (hentai behavior, effeminate tendencies, macho overprotection, emotional hangups or hot-buttons, etc.) which is really refreshing to this anime fan.
The main drawback that I see in the character is the too-wholesome restraint that's imposed on his expressed urges to maim, torture and kill people. Only in flashbacks and the amazing battle with Kenshin was the full fury of Mibu's Wolf shown. I'd really like to see some kind of side story where Saitoh gets to show off his investigative skills (he probably is a really good cop), his leadership skills (how does he treat his team/department?), and of course, his fighting skills and ascerbic wit (gotta love those battles and running commentary). Maybe a long time from now I'll write a story like that, but I'd much prefer to read one.