Goryomaru lives in an old temple with a group of orphans who lost their parents to demons. The orphans are not only under Goryomaru's care, but his tutelage as well. Although these child soldiers have limited training, Goryomaru sends them through the countryside hunting demons by using strange-shaped jars that emit energy siphoned from Goryomaru's deformed arm. Inuyasha and Goryomaru quickly develop an adversarial relationship, due to the fact that Goryomaru is extremely cryptic about his motives.
Eventually the monk reveals that he was attacked by a demon who attempted to absorb him. Goryomaru was able to prevent the creature from overtaking him, which resulted in the strange laser-like cannon that now replaces his right arm. The scars from this battle cover Goryomaru's face and throat and serve as a constant reminder of the savage battle.
Eventually Goryomaru's slaughter of demons brings him to the attention of Hakudoshi and Kagura. Kagura quickly falls to Goryomaru's cannon arm, after having a giant hole blown through her chest, nearly killing her. It is then that Hakudoshi attacks and decapitates Goryomaru. With Goryomaru dead the demon parasite that formed the cannon is able to escape once more and reveals itself to be the souless golem Moryomaru.
The Meaning Behind the Name
Goryomaru's name breaks down to "full of spirit" with the suffix maru, which is a male name ending. Basically Goryomaru means "soulful man" or "spiritual man".
Masaki Terasoma & Ross Douglas
The mysterious Goryomaru is played by Masaki Terasoma who could previous be heard as Koskue Niwa in D.N.Angel, Azuma in Ghost in the Shell: Innocence and Kambei Shimada in Samurai 7.
Goryomaru's English voice actor, Ross Douglas, has played the Narrator for Mobile Suit Gundam, Shintaro's Father in Inuyasha, Daniel O'Connell in Master Keaton and Kageyama in Black Lagoon.