The new girl Toa can be developed by giving her unique powers. For instance, if she has the power to communicate with nature in a way other Toa can't. Her relationships also play a big role. If she has a mentor, like an older, experienced Toa, she can learn from them and grow. This relationship can show her naivete at first and then her increasing wisdom as she trains.
One great Bionicle Human Toa fanfiction is 'The Ascent of the Toa'. It focuses on the humanoid Toa characters and their journey to discover their true powers. The story has really engaging action scenes and well - developed characters.
Julius Caesar's story is based on actual history. While some details might have been embellished or simplified for storytelling purposes, the main events and his existence are factual.