Ellie Darcy, or The Secret Darcy or Lady Darcy, is the mysterious girl who was created by Mayor Willson. She reveals to be Cillian, Lorcan and Lilly Darcy, Ed Edd and Eddy's half-sister. In the finale ofMy Name is Ellie Darcy, She injects Lorcan with the chemical and reveals that she is the Secret Darcy, Mayor Willson and Queen Emily Darcy's daughter, revealing her relationship with Lorcan as an plot to seek revenge for murder her father.
After waking up, Lorcan vow to rescue her from Milton Grimm. She first appeared in The Medieval Journey, she shows a flirtatious attitude towards Lorcanin their early encounters. The first time they meet, Ellie compliments how she was "excited to see him battling." She also hugs him, winks at him, and blows him kisses and calls him things like "sweetie-pie" throughout.
She appears in The Medieval Journey as the true main antagonist but later reforms and makes her the supporting protagonist in The Darcy Triplets Story. She gains her warrior form to join a duel with her half-siblings against Phineus Phibes in their final batle.