The main themes in this graphic novel include the idea of destiny. The characters seem to be on a path that is somewhat pre - determined, yet they still have free will to make choices. Love is also a theme. Romantic love, as well as love for one's country and comrades, is explored. For example, the relationships between the characters are often influenced by their feelings of love, and this affects the decisions they make throughout the story.
Well, in 'the once and future king graphic novel', the themes of loyalty and betrayal are quite prominent. The characters often face situations where they have to choose between being loyal to someone or betraying them for their own gain. Also, the theme of chivalry is there. It depicts the knights' code of honor and how they are supposed to behave in different situations, which is an important part of the overall story.
One of the main themes is the concept of kingship. It shows different aspects of what it means to be a king, like leadership and responsibility. Another theme could be the cycle of life and death as seen through the characters' experiences.