Nerokage, a.k.a. Evil Terrence, is the evil clone of Terrence Silva. He and Terrence fought one another time and again. No matter how many times he was defeated, he manages to come back to plague his good counterpart time and again. This makes him Terrence's arch foe and one of the most dangerous of Terrence's enemies. Terrence even considers him both his clone.... and his curse.Out of spite for his brother becoming the Dragon Halfa, Alister created Nerokage for the purpose of destroying Terrence.
His main goal is to merge with Terrence to become a powerful being. He succeeded in doing so once, but was separated thanks to Sirius Black.
He was later seen as a cyborg. He attempted to merge with Terrence again when the dragon halfa went to fight his brother, Alister, but one of Terrence's spells hindered him in doing so. But Nerokage knows that when Terrence uses his powers, it weakens the seal that prevents him and Terrence from merging.
By the time Terrence's seal was broken, Terrence went to fight him one on one without the knowledge of the rest of the Guardians. By the time the rest of the Guardians came to help Terrence, Nerokage eventually got the chance and merged with Terrence once again, giving the the Guardians a hard time. But a fragment of Terrence consciousness is still intact allowing Terrence to temporarily communicate with the Guardians.
In the first Majestic Guardians Movie, he was freed from his icy prison and wished to merge with Terrence once again, only to be beaten and destroyed by him. In another movie, he and Shadow Gwen were resurrected as Night Terror and Tigris respectively due to the energy output from Excalibur. They attacked Edenia with a legion of the undead along with Vanitas, who has merged with Ven. He was eventually destroyed by his good counterpart once more, and that's probably the last we see of Nerokage.
in Fearless Slayers Move: Daemon's wrath, He appeared when he made a deal with Daemon. It was also revealed he made three clones of himself. He made cameo when he was watching the footage of the Majestic Guardians and the Cosmatic Crime Fighters destroying his clones. He send his Cyborg Nerokage to destroy the Fearless Slayers.
He made his final official apearance in the two parter, Fearless Slayers: Nerokage Final Battle, where he had his minions, Constricta and Ssielk Nav to forge the Eight Orbs of Sin, which he absorbed, turning into the ruthlessly demonic Devil Nerokage (more information here).