Darth Manacore first came to be when Brian was being seduced to the dark side. Then when Gleaming Shield and 3 other Royal Guards confronted Nightmare Moon and King Sombra, they broke into a duel as Brian flew a shuttle back to the Castle. As Gleaming Shield had Nightmare Moon and King Sombra at Saber point, And just before he killed them, Brian drew his own Saber and disarmed Gleaming Shield. Which gave the 2 Dark Lords the chance to fire Force Lightning at Gleaming Shield and then throw him out the window, down to his doom. Brian was at first shocked at what he did, but after Sombra spook to him, Brian then agreed to join his side and become his apprentice. as Sombra then officially deemed him, "Darth Manacore." Then now as Manacore, Brian helped the Changlings attack the Jedi Temple, as he killed the Jedi younglings, Royal Guards and other Jedi Knights using his saber, M16, & pistol. Then Nightmare Moon and Sombra then told Brian to go mock the team. as Manacore confronted the team and made rude remarks at the team, throwing insults, mocking them, and then shouted at the Eds for not inviting to join the Adventure with the The Dragon Emperor. And then left the room. As the team then replayed the security recordings to found out what Manacore did. As Zecora left to confront the Dark Lords, The Sparkles told Sylveon what was up, but discouraged Sylveon flew to Cloud City. (where Brian was sent to terminate The Droid Leaders, Crusts, and Biskits.) And Sylveon met with Manacore.
But Manacore, discovered that the Sparkles had revealed Manacore's dark deeds in the Jedi Temple to her. Though he did not deny the accusation, Manacore maintained that the Sparkles were only attempting to turn her against him. Sylveon tried to reason with him, convince him to retire from public service with her to raise their family, but Manacore countered with his plan to overthrow Nightmare Moon, King Sombra, Queen Chrysalis, and Discord and set the both of them up in his place. Shocked and horrified, Sylveon refused, stating that he had changed and was going down a path she could not follow. She pleaded with him to come back, promising she still loved him. However, unknown to Sylveon, the Sparkles had stowed away on her ship to find Manacore, and at that moment he appeared on the ship's ramp. Upon seeing them Manacore incorrectly assumed Sylveon had betrayed him and brought The Sparkles to kill him. Overwhelmed by his anger and rage, he lashed out with the Force, choking his wife into unconsciousness, ignoring her tearful pleas of innocence. The Sparkles also tried to reason with him, but Manacore refused to listen, too consumed by hate. After The Sparkles resolved they had no choice but to fight, Manacore told them they would try, and leaped to attack. And an intense duel broke out, using their Sabers, hands and hooves, and other things. Till they came to the bridge as The Sparkles took to the high ground, but Manacore consumed by Rage and overwhelming Pride, Manacore attempted to make the same jump, but in the middle of it Vinny shot him and stunned him. The Stun shot managed to snap Manacore back into regular old Brian.
As Brian woke up, and Sylveon told him what happened, and scolded him for letting his jealously and anger control him, as she went to join the battle (after claiming Brian is no longer considered her husband), then Brian rushed out and in an effort to redeem himself for the Dark deeds, Brian jumps in the middle of a dark magic and Force Lightning blast produced by King Sombra meant to kill The Sparkles, Thomas, The Royals, and Sylveon. But the blast had killed him, but in the Afterlife, Yoda, Obi-Wan, and Anakin revived him. As the team confront the Nightmare Family, Chrysalis, and Discord and Nightmare Hiro, Sombra was enrages that his apprentice turned against him and a duel broke out but the Team overpowered them and the villains are sent falling from Cloud City to their dooms.
In "O'Diesel Strikes Back,"
Brian is now suffering from several Nightmares from his near fall to the Darkside. The First one where during the duel in Cloud City, when Brian they to jump at the Sparkles, but the Sparkles cut off his arms and legs in the mid-jump, and as the Sparkles left, (taking Brian's ordinary Lightsaber with them) And after the battle was complete, the team left Cloud City, as the Dark Lords picked up Brian. And took him back to the Nightmare castle, where they gave Brian a full metal armor suit and helmet making his voice sound electronic, officially making him Darth Manacore. But with the Team, they found out that Brian's Force choke had put Sylveon into a coma. Which Manacore sensed (but thought Sylveon was actually dead). In which made Brian wake with a start.
Then in a second Nightmare,
Darth Manacore is
Darth Manacore wears a black suit with cybernetic Hands and feet, gray and light blue armor with a Blue Crescent Moon on the breast plate. With a metal mask that made Brian's ordinary voice sound electronic, with a black and Blue helmet. And wears a black utility belt with Blue boxes and a clip for his Blue and Dark Red Dual-Phased Lightsaber.