Caius has a open-minded and devoted personality towards his fellow subjects and foreigners. When it comes to someone close to him, Caius is very kindhearted and cherishing towards that individual. However, Caius can also be serious, demanding, and violent to those that don't listen and harming the one's close to him. He showed determination in never giving up researching how to learn summoning magic. A similar attitude was shown in his desire to gain the throne and his beloved.