Catania is an original character created for The Shannara Chronicles. She was the friend and handmaiden of the Elven princess Amberle Elessedil, though her role was closer to that of a lady-in-waiting.
Along with Amberle's uncle Ander Elessedil, Catania is one of the only people to know of and support Amberle's plans to run the Gauntlet in the hopes of becoming a member of the Chosen. Catania was dating a member of the Chosen named Jase, and she is devastated when he and the rest of the Chosen except for Amberle are killed by the Changeling.
Later in Arborlon, Catania accidentally runs into Bandon, causing Bandon to have a vision of her death. Acting on his vision, Bandon manages to save Catania from being stabbed by the Changeling. After this incident, a romantic bond begins to form between the two Elves.
When the Druid Allanon begins training Bandon in the use of magic, the Dagda Mor takes notice and seizes Bandon's mind, locking it away from Allanon's reach and incapacitating the boy. Both Allanon and Catania are watching over the unconscious Bandon when the Dagda Mor uses Bandon to grab Allanon and put the Druid's mind under his control as well. Under the Demon's influence, Allanon begins choking Catania, but the Druid is able to free his mind and stop himself just after Arion Elessedil appears.
Arion, who had already been suspicious of the Druid, is convinced by this display that the Druid must be taken out and asks a frightened Catania to help him find the Warlock Sword, because Catania is knowledgeable about the tunnels and passageways under the Elven palace where the sword is supposed to be kept. Together they find the sword in little time, and Arion later runs the Druid through with the sword, apparently killing him.
Later, during a confrontation between the Dagda Mor, Arion, and Ander Elessedil, Allanon manages to free Bandon from his mental imprisonment. He tells Bandon that he wants to train him to become the next Druid, the same way he was trained after his own parents abandoned him. Bandon refuses, but Allanon insists that under the current Demon onslaught, he doesn't have that choice anymore.
As Allanon begins teaching Bandon to harness his magic properly, Bandon becomes resentful of the Druid's harsh training and preoccupied with the feeling that he is only being valued for and defined by his magic. It soon becomes apparent that the Dagda Mor's hold on Bandon's mind has not been completely undone. When Bandon and Catania are alone together, he confesses to her that he still feels the Dagda Mor's presence, and Catania encourages him to fight it. They kiss, but as their intimacy begins to increase Bandon gets a vision from the Dadga Mor and ends up trying to strangle Catania. She manages to get away, and Allanon decides to hide her from Bandon for her own safety.
Later, Catania is seen visiting Bandon and bringing him food to his prison cell in Arborlon. He convinces her to help him deceive a guard into unlocking his shackles, but after he is freed he flies into a rage when the guard manhandles Catania. To Catania's horror he doesn't just incapacitate the guard; he brutally beats him to death. Bandon flees and is later seen carrying the Warlock Sword, standing at the magical henge where the Dagda Mor had once imprisoned his mind.
Catania is left to explain to Allanon what had happened. She tells Allanon that she has failed Bandon, and the Druid commiserates with her, saying that he's failed Bandon as well.