The legend of Lord Demanitus was first mentioned by Xavier in "Queen for a Day". Demanitus was in a constant battle against the evil warlock Zhan Tiri and his servants. Years later, Zhan Tiri casts a spell to cause the blizzard and storm sweeping across the land of Corona. Demanitus used both magic and science to build the machine deep in the Corona mountains and change the direction of the wind. He successfully defeated Zhan Tiri and saved the day. Over the years, Demanitus captured many of the evil spirits and imprisoned them in the chamber of the machine.
Demanitus and three of his pupils researched the legend of the Sundrop and Moonstone, two elements created and were divided by a mysterious cosmic event that are longed destined to be reunited. Alas, they were unable to find them, unfortunately, they weren't the only ones searching. Demanitus' pupils suddenly betrayed him and summoned his old nemesis, Zhan Tiri, whom Demanitus eventually banished back to his own realm. Demanitus knew his research of the Sundrop and Moonstone was too valuable, so he decided to tear the scroll containing his research into four pieces, which were scattered across the world, preventing them from falling into the wrong hands. The final piece was placed in a maze to keep out those who are unworthy.
To avoid Zhan Tiri's searching, Demanitus used his scientific acumen coupled with an ancient spell to inhabit his spirit into a monkey named Vigor. However, his conscious was only able to dominate Vigor once for a few hours, which Demanitus saved for his destined encounter with Rapunzel. After his role is fulfilled, Demanitus' spirit would retreat into Vigor's body forever.
Role in the series
Demanitus was first mentioned in "Queen for a Day", when Xavier told the story of the Demanitus Device to Rapunzel and her friends. When Zhan Tiri's snow storm hits Corona, Rapunzel uses the Demanitus Device to save her kingdom.
Lord Dermanitus is mentioned in "Rapunzel and the Great Tree". As told by Adira, when Zhan Tiri took over and corrupted the Great Tree he put a stop to his reign with a magic spear that rendered the evil magic in the Great Tree dormant. Since Hector discovered the Heart of Zhan Tiri's Tree, he says to Lord Dermanitus to forgive himself "for unleashing the evil that sleeps within".
Lord Demanitus appears again in "Lost and Found", inhabiting the body of Vigor. While controlling Vigor, Demanitus guides Rapunzel and Eugene through his maze to recover the fourth and final piece of his scroll. Shortly after retrieving it, Demanitus' spirit merges into Vigor's body completely.