The story likely involves the adventures and challenges faced by the knight king who comes back with the aid or presence of a god. Maybe it's a tale of redemption, conquest, or some other epic journey.
The story focuses on the knight king's journey after being bestowed with god-like abilities. It involves battles, quests, and the rediscovery of his purpose.
King Arthur is more powerful. He is the king with noble qualities and represents good. His power comes from his courage, leadership, and the righteousness of his cause. The Black Knight may be a strong opponent, but Arthur overcomes him in the end, showing Arthur's greater power.
As I'm not acquainted with 'kenrith the returned king story', I can't name the main characters. However, in many stories of this kind, there are usually a hero or heroine, perhaps some loyal sidekicks or mentors. But in this case, we really need to study the actual story to determine the main characters.
The main characters are the king and his knight. The king could be a complex character, with his own backstory, motives, and insecurities. The knight, on the other hand, may have a reputation to uphold, a code of honor to follow. There might be other characters like the queen, who could add more drama to the story, or a jester who provides some comic relief, but the king and his knight are bound to be at the heart of the narrative.
I don't know who the author of 'the king of god novel' is. There are so many novels out there, and without more information, it's difficult to determine the author.