Gamuran (我無乱 Gamuran), is the main antagonist of Shinobido: Way of the Ninja.
A yamabushi, he was an ancient enemy of the Asuka Ninja and was imprisoned by them in a shrine for 900 years. He wanted to obtain the secrets of necromancy and fought for a scroll that held this power. He is accidentally freed by Goh and proceeded to destroy the Asuka Village soon before the events in the game, leaving an amnesiac Goh, Zaji and Kinu as the only remaining Asuka Ninja.
900 years before the events of the game he attempted to attain the power of the scroll of necromancy for himself but was defeated in battle by another ascetic who used a sacred sword to entrap his soul inside it. The ascetic later built a shrine for the (now possessed) sword and founded the Asuka Ninja Clan, who inherited the task of protecting both shrine and scroll.
Way of the Ninja
Some time before the start of the game the shrine was opened by a curious Goh and a reluctant Kinu. Gamuran used this opportunity to attempt possession on Kinu, and while she managed to avoid possession by having her right arm amputated Gamuran still managed to escape in spirit form.
Presumably after this and before finding Goh again he met an ascetic monk by the name of Onji and in an act of cruel pettiness and to test his powers removed the monk's soul from his body and sealed it inside a cat. Little did he know how much the cursed monk would aid in his defeat.
He met Goh once again and gradually influenced his actions. It was under this influence that Goh murdered Tateha even against orders and confessed clan secrets and weaknesses to Gamuran. Goh manages to break free almost too late, as the Taraba start the massacre of the Asuka, and find the dying Master Taiga who instructs him to find the scroll of necromancy and destroy it. Gamuran finds Goh a split second after he find the scroll and demands it's return, but Goh destroys the scroll instead and Gamuran uses his sorcery to extract Goh's soul for his memories of the scroll's texts.
Perhaps due to Gamuran's incomplete powers the spell is botched, Goh retains his body but loses all his memories, now scattered through Utakata in the form of Soul Fragments. In the aftermath of the massacre two other ninja survive: Zaji and Kinu.
He continues to employ the Taraba Ninja to collect the Soul Fragments for most of the game. During a meeting in the Phantom Forest Gamuran reveals his intent to use the necromancy scroll's secrets to return his body to flesh along with his full powers in a ritual under the full moon, but the Taraba leader Kabuto tries to "control" Gamuran with a Soul Fragment, completely ignorant to its purpose. Gamuran simply mocks his stupidity and uses his telekinesis to turn the Taraba's bombs on them when Kabuto orders an attack. Unbeknown to both a spying Kinu managed to hear of both Gamuran's involvement and the full moon ritual.
The last Soul Fragment, the one containing the necromancy scroll texts, is revealed to be inside a whale statue in the recently-completed Utakata Castle. As Goh passes through the Phantom Forest to arrive at the castle he encounters Gamuran, who this time succeeds in removing his soul and traps him inside a bear's body. In this form the disoriented Goh is captured by soldiers and taken to the castle, but escapes and becomes involved in a four-way battle with Uzumushi, Usuba and Kinu.
Due to all clans being distracted by fighting in Utakata Castle, Kabuto finds the last Soul Fragment hidden in the whale statue's eye without trouble and delivers it to Gamuran. It's at this point that the daimyos become aware of the sorcerer's existance and the danger he poses to their plans, and depending on the player's progression they negotiate a truce against their common enemy or the victorious daimyo directly orders Goh the extermination of Gamuran.
Either way the Asuka arrive to the village and try to sneak to the shrine, but Kabuto and his troops spot them first and ambush Goh and Zaji, either killing or severely injuring the latter (depending on the ending taken). Goh fights and kills Kabuto before facing Gamuran himself. He fails to stop Gamuran's resurrection, rendering the sorcerer virtually immortal, but Kinu takes the sacred sword in the shrine to fight back. Gamuran tries to kill her but Onji intercepts the strike. Goh takes the sacred sword, the only weapon capable of harming the sorcerer, and uses it to finally kill his clan's ancient enemy.
Tales of the Ninja
Gamuran remains dead in this game, but one mission reveals that his memory still haunts Goh's nightmares.
Despite his limited spirit form Gamuran retains many dangerous abilities the most notable is the power to extract the souls of people, which was used against Goh in two ocasions and against Onji who was less fortunate.
He can also use telekinesis to move objects. He uses this ability to stop Kabuto's bombs in a cutscene and as an attack during the final battle. He can also float to a limited extent, probably using telekinesis as well.
He manages to resurrect himself after discovering the secrets of necromancy. It's also explained in cutscenes that this forbidden art would have let him raise an army of the dead at his command, as was always his intention.
It's implied he used to be more powerful in life, this and his evil ambitions being the reasons for his sealing. Even after his resurrection the full extent of his powers is not shown.
It could be said that Gamuran's most notable trait is his unhibited ambition, that unlike the daimyo's does not take in consideration the wellbeing of the people or the land. His sole desire is to make the world his property, and he is more than willing to trample anyone on the way. Not even being killed and sealed for 900 years quelled his greed.
Gamuran is purely evil and sadistic, with no empathy for other living beings. He curses and harms others, even if they are not an obstacle to him like Onji initially was. He is especially cruel to those who are a threat to him, as his manipulation of Goh and the destruction of the Asuka can attest.
He can be easily related to the stereotype of the Evil Sorcerer
Gamuran was accidentally freed by Goh when he opened the shrine out of curiosity. The sorcerer later manipulated him into revealing the location of the scrolls and his clan's weaknesses. It was Gamuran who removed Goh's soul, along with his memories. In one occasion he attempts to curse the ninja the same way he did to Onji, but fortunately Goh recovers his body before it's too late. The vitriol is more evident in the final battle where Goh is at his most furious, when in battles with other opponents he would remain mostly neutral, as Gamuran countinues to taunt and rile him up.
Being his biggest mistake and the killer of his clan, Gamuran becomes Goh's nemesis. And perhaps it's the trauma of his actions that makes the sorcerer haunt his nightmares even after his final death.
Onji was Gamuran's first victim after his soul was freed. The sorcerer encountered him during pilgrimage and out of spite tore out his soul and trapped it in a cat's body, dooming the monk to slowly lose his human identity. Despite his condition Onji made it his personal task to stop Gamuran, advicing and helping the amnesiac Goh in the same mission.
Gamuran contracted the Taraba clan to wipe out the Asuka and then find the Soul Fragments for him. Kabuto however had no sense of loyalty to the sorcerer and once tried to betray him but failed. It seems the only true reason for the Taraba's compliance is fear of Gamuran's power. The sorcerer also has no trust in the Taraba, as he never explained the purpose of the Soul Fragments and his plans to them.
The Asuka Ninja
900 in the past an ascetic defeated him and sealed his soul in a sword. The same monk then founded the Asuka Clan to protect the land and keep Gamuran sealed, he became the clan's ancient enemy. Upon being released, he manipulated Goh and contracted the Taraba to completely destroy the Asuka, both out of revenge and to get rid of his biggest obstacle.