Selym Idur is a former minor character in the Duo-Franchise, the tertiary antagonist, also anti-hero of the first half of Duo-Franchise: Carnaval Style and a deuteragonist of the Duo-Franchise continuity serving as a main character alongside his teammates.
Though turned into a snake pre-Swordsday Conflict, he didn't have a major role up until that episode. In said episode, he developed a rivalry with Zachary and faked a backstory thanks to the writers. However, because of a betrayal by Yntom Idur (Selym's more crazed brother), his rivalry with Zachary didn't last long and he managed to fight against his brother. As they were about to get along, he reveals his true colors and turned against Supervision and Water Witch as well as assaulted the Carnaval party. As a result of his actions, Monogram loses his job as well as his company and wealth which leads to him destroying the lair and causing the Myles Bots and their benefactor's family to relocate. Despite laying a fatal incident on the agency, his plans have caught the attention of the Space Tree and they send in Dr. Reuben Langer again which prompts the start of the next episode as well as becoming a catalyst for the Bots becoming the Dome's next target. Later, when the villain arc was scrapped, he returns to the series back to being a human and originally turned into a raccoon though it didn't last long. Following the apparent death of Black Ranger and Simba's fall from grace, Selym officially joins the cast though remained noncorporeal for the entirety of the August Arc.