Sym-Bionic Titan: Heiress of the Legend (also called Sym-Bio: Heiress of the Legend, or SBT:HotL) is an unofficial sequel to Cartoon Network's action series Sym-Bionic Titan. The main focus is on the adventures of Ilana and Lance's daughter, Adriana Lunis, on her quest to stop the advancing threat of General Modula Jr's world domination plans. Adriana is capable to form the Sym-Bionic Titan togteher with her friend Drew Hall and her android guardian, Athenea.
- Adriana Lunis is the daughter of Princess Ilana and Corporal Lance, and the main protagonist of the series. She is a teenage girl who, despite looking like a traditional brunette girl of her age, displays a laid-back, yet devoted personality. She is not only easy to get along with, but also a dedicated, intelligent and clever individual.
- Drew Hall, son of Dr Dexter Hall, is the closest friend of Adriana. He has a more serious personality than Adriana, but he is as still intelligent and clever. His skills as an inventor leads him to collaborate with Adriana, eventually leading to the "creation" of the Sym-Bionic Titan and Adriana's guardian, Athenea.
- Athenea is the andriod guardian of Adriana. She is technically a female android invented and designed by Drew being constructed on Detroit. She is initially a cold, soulless machine, but as the series progresses, she develops a human behaviour thanks to upgrades made on her by Drew, eventually becoming friends with Adriana.