After letting it digest a bit, I laughed manically when I realized I could combine my 3 favorite pieces of Samurai Lore in a single character.
The Shinsengumi were the closest thing to "Hardcore" the samurai class had before they modernized AND they are the only group with the audacity to wear these bright blue uniforms. A samurai who's technically "A Boy in Blue" is just funny. Plus, the psycological effect of blue is well documented.
But, I thought of something 10 times better. I still need helps working out kinks and some forum goers find this idea amusing, so let's keep going.
Name: ? Temp Name(So he's not just that guy): Toshiro
I still don't have a good name other than a historical moniker.
High Concept: Ronin Sword-Saint
Let's face it folks Master Swordsmen are cool. If they weren't, maybe Shiro would have been a Shaolin Monk instead.
My little contribution to the ever-expanding Dresdenverse. A Kensei or "Sword-Saint" is a swordsman of legendary skill. My take on it is that in feudal Japan Kensei were more than just good swordsmen. In this case, the term "Sword Saint" was more literal, referring to a naturally occurring Ascended Human. Some of the Schools(As in fighting styles) of Samurai arts as taught in Schools (As in institutions) in feudal Japan were actually carefully designed rituals that would eventually cause their practicitioners to ascend, making them literally a Saint, a Buddha, a Kensei. But, it was only certain styles and if some of the rites broke some of the Laws of Magic (Human Sacrifice via Battle Anyone?). then maybe the White Council had a hand in the moderization of Japan which I would also find Hilarious.
Adding, Dishonored to the Aspect could give more depth, if he even cares about honor.
Trouble: I Followed My Love Across Time
However the hell he got here to 2010, he needs a reason to. My first thought was to say he's been around that long and give him an aspect like...Long Lived but Not Long Memoried, and I'm still tempted to to counteract the fact that most long-lived things in the Dresdenverse age like wine or cheese rather than like a regular human.
Then it just hit me and I wrote, I Followed My Love Across Time. Obviously, he was or still is following someone through the ages. Doing the Inu Yasha thing it could mean a soul mate that keeps getting reincarnated. Plus, love continually biting a character in the ass is par for the course in the Dresdenverse.
A strong contender for a Trouble was A Small Speck of Bushido Left. But that relates to his Phase 1.
Phase 1 (Where Did You Come From?): Hitokiri Kyouken: The Dog of Mibu
Toshiro of the town of Mibu was a teenager from an unimportant family when he joined the Shinsengumi. A Prodigy with a sword, he fit right into the hardcore group of Samurai. He taught himself the written Japanese language as well as English and Dutch. His outstanding combat record and utter adherence to Bushido earned him quite a reputation as a poster child for the Samurai Class.
He also had a love on the side, a soulmate who had talent with Magic. She wanted to abandon the life of a warrior and marry her, but he could not give up his way of life. Toshiro did promise whenever he went out to battle that he would return.
Unfortunately, the Shinsengumi were among the losers of the Meiji Revolution. There were Shinsengumi survivors of the Revolution, but most of them were people who surrendered. Toshiro was the vice-commander of the faction that believed they should die to a man in the face of overwhelming odds. In the final battle, he was faced with hopeless odds and the prospect of not being able to return to his love. His commander told them to to die fighting, but Toshiro said, "Screw it" Toshiro, paragon of the Shinsengumi did the unthinkable, he stabbed his commanding officer in the back, killing him. He ordered his unit to stand down. The unit didn't agree with that.....
In that moment, he unexpectedly cut a hole in the Nevernever and escaped.
His unit was wiped out, but Toshiro is recorded in history as a disgrace and his treachery was so unexpected that history him as the Dog of Mibu, Hitokiri Kyouken.
During the Meiji Revolution, 4 Samurai were retrospectively given the title of "Hitokiri" which means manslayer. these 4 were the best and were thought so skillful that they could not be defeated my normal people. These 4 are so popular, the Rurouni Kenshin franchise has made bank using this title normally used to refer to just these 4 to refer to quite a few more.
Creative license led to the name with mates Hitokiri with the word for Mad Dog.
Phase 2 (What Shaped You?): Musashi Miyamoto's Last Student
When Toshiro escaped into the Nevernever he wandered a while. He ended up at the feet of the legendary Musashi Miyamoto, who was also a Kensei. Musashi rebuilt Toshiro, sent him on quests to better himself(including obtaining his own Masamune) and sent him on a journey to find his lost love.
Toshiro's journey landed him in the modern world.
The Book of 5 Rings is awesome read and of all the takes on Samurai, MM's is the easiest for me to grasp because it is so pragmatic. Plus, MM's stories are the coolest sounding.
That's all I got. I don't know what other Aspects to give him.