Luna

History
Luna was the daughter of Blackfur, leader of the Wolf Tribes; when she was still a baby her Tribe was attacked by Sinistra who sought the territory their Tribe was on, hence she massacred the Wolf Tribes, leaving only Luna as a survivor. Sinistra kept Luna, and raised her as her pupil, teaching her everything she knew in Dark Magic.

Growing up, Luna kept working for Sinistra until she witnessed Starshades exposing what really happened; Sinistra had told Luna that Merlin killed her parents, and that Sinistra took pity of her and accepted her as a pupil to save her, but seeing the scene before her made her realize Sinistra's lies and turned on her, joining the Warriors of Chronos.

As a Warrior, Luna's magical abilities matched Johnny's, which made it so the both of them could help each other with their learning of spells and magic. Personality-wise, Luna was tough and stubborn, a hard shell hiding how emotional and soft she really was. In the first season of the TV series, Luna and Mika were shown to have feelings for each other; despite it leading to nowhere as it was never mentioned in the second season, a lot of episodes were centered around their hidden feelings for each other.

Luna was the center of two story-arcs, the first one, "Blackfur", showed Luna learning the truth about her parents death and turning against Sinistra. Then, in "Luna and the Warriors of Chronos", Luna visited a parallel dimension where the Wolf Tribe was never destroyed by Sinistra, but the Amazons did. In this dimension, Luna never became a hero, she stayed and lived a regular life with her parents, as Johnny was Sinistra's pupil. Luna learned that she wasn't to blame for what she did in the past, she was young and influenced by lies Sinistra told her. She was able to turn Johnny into a hero in this dimension by showing him how his parents really died-- by Sinistra, who also lied to Johnny.