Souji's appearance is that of a man in his late twenties.
He wears the traditional Shisengumi uniform, which consists of a haori and hakama over a kimono, with a white cord called a tasuki crossed over the chest and tied in the back. The function of the tasuki is to prevent the sleeves of the kimono from interfering with moving the arms. The haori is colored light blue, one of Japan's traditional colors, and the sleeves were trimmed with "light mountain stripes".
Souji has shown himself to have a very laid back personality. He is even able to remain calm when Grayfia gets angry (while everyone else is terrified).
He was the captain of the first unit of the Shinsengumi, a special police force in Kyoto during the late shogunate period. He was one of the best swordsmen of the Shinsengumi, the only one who mastered the Tennen Rishin-Ryu at the age of 18. During one of the many rituals to avoid dying from tuberculosis, he met Sirzechs by accidentally summoning him. He was later revived as a Devil by Sirzechs Lucifer as his Knight some time after his death in the Boshin War, and taught Yuuto Kiba kenjutsu some time before the series began.
Powers & Abilities
Demonic Power: As a Devil, Souji has all the common skills and powers of one.
Immense Speed: As a Knight that consumed 2 Knight Evil Pieces. Souji is capable of moving at God-like speed that is almost impossible to see.
Master Swordsman: Souji is a tremendously skilled master swordsman, during his life as a human, he became a master of Tennen Rishin-ryu at the age of 18 and is considered to be one of the best swordsmen of the Shisengumi. After he was reincarnated into a Devil as a Knight by Sirzechs, Souji's prowess in swordmanship greatly enhanced by his Devil physiology and Evil Pieces's trait as a Knight. Souji could sliced the right leg of the Jabberwocky, a gigantic 200 meter tall monster with great ease.
Magic: Souji has some knowledge in magic, having perform magic rituals many times in his life as a human to stop himself from dying from tuberculosis, even managed to summon Sirzechs as well as magically modified his body into a nest for Youkai.
- Summoning Magic:Souji can use summoning magic, as he managed to summoned Sirzechs by chance.
- Living Hive: Due to the many rituals and such that he did in the past, his body was magically modified into a living nest of Youkai and he can release them from his body to attack his opponents.
Katana: Souji's primary weapon as a former Shisengumi samurai and Sirzechs's Devil Knight.
Youkai: Souji has many Youkais such as a Nue residing inside his body which he can release to attack his opponents.
Knight Piece (騎士の駒, Kishi no koma): Souji was reincarnated using two Knight Pieces, which enhances his speed, making him faster than an average person, and more than most Knights.
- Souji is the first historical character featured in the entire series to be introduced (Members of the Hero Faction do not count, as they are descendants of legendary/mythological heroes).
- Souji is the main reason of Rias' interest in Japan, as the weird knowledge of the Samurai is also one of his naughty habits.
- In the third season of the anime adaptation of volume 6, Souji made a cameo appearance during Kiba's training, with only his Shinsengumi pattern haori in view. In the manga, his arm and sword is also included in the shot.
- In history, the day Souji died which was on the 19th July is by the lunar calendar the 30th May which is Yuuto Kiba's birthday.
- High School DxD Light Novel Volume 13 Extra Life