The first thing one notices about Tomo is his garish attire. This is apparently the costume of a high-ranking general in Chinese Opera. The crown and ho feathers symbolize power and warrior spirit. The long nails are a status symbol. Tomo's makeup, as I think he once explained, goes like this: black for moderation or loyalty, indigo for the development of strategies and gold to represent harmony. The white base indicates an evil character.
In these clothes, Tomo is a cool, confident, sadistic bastard, but without them, he defines insecure (childhood trauma?). Tomo is very clever and efficent, a briliant strategist, and he would do anything for Nakago who he loves (yep, he's gay). In fact, as he dies, with his last breath he begs for forgiveness for his failure. Tomo is very devoted to Nakago and would send instant retribution against anyone who tried to hurt him. Because of his feelings, Tomo doesn't get along well with Soi who he considers to be a rival, competition for Nakago's affection.
Tomo is a bit of a loner, but he can work with Soi when he has to and he almost seems to have an understanding with Ashitare even if he doesn't much like him.
The best Tomo fanfic I've ever read, From the Ruins of Childhood. Go read it!
