Shasuke is quite a short individual who is described to always wear a black cloak that covers his entire body. He also wears a mask on his face, and a hachigane on his forehead. When he took off his cloak, his body was described to be quite pale, with an eerie blue mottled pattern covering his torso.
Shasuke has quite a humble personality, serving his master without complaint. He did not feel any emotions until the very end due to the Shinobi training process stripping them from him. Just before his death, he was described to have finally been happy, and was finally able to laugh louder than he ever had in his life.
Raizo and Shasuke were born in a Shinobi village in Vollachia. The two of them were twins who were subject to the training process of a Shinobi. The process was cruel, and involved body modifications using drugs, magic and heavy training. It was mentioned that only 1 in a million could survive this process. But both he and Shasuke survived and were reborn as Shinobi. They became the pride of their village. However, as the Empire feared the village's strength, one day, when the two of them were not at the village, they sent some nobles to burn it down, killing everyone there. It was then that the two Shinobi met Stride who offered them revenge against the nobles. After killing the nobles, the two Shinobi devoted their services to Stride.
Shinobi Skills: Shasuke is apt in the use of kunai, and in fighting using martial arts. In addition to that, it can be expected he has multiple skills that were unnamed, as we saw some examples of one which allowed Shasuke to attempt to transform his body into steel, before it was interrupted by Carol.
- Shadow Form: Shasuke sinks into a person's shadows, and becomes part of it. He can use this ability to carry people into them and transport them to his brother, or to hide. Furthermore, he can use this ability to appear in another person's shadow.