Since it's a story about Camelot, King Arthur is almost surely a main character. He is the king around which the whole Camelot legend revolves. His knights, who are known for their bravery and chivalry, would also be important characters. If the Sangrael is a significant element in the story, there could be a character whose sole purpose is related to it, perhaps a guardian or a seeker. And of course, characters like Guinevere, Arthur's queen, could also be among the main characters as she is often part of the complex relationships within the Camelot story.
Most likely King Arthur, his most famous knights like Lancelot and Gawain could be main characters. Also, if there's a focus on the Sangrael, maybe a character who is in charge of protecting or searching for it. Merlin, the wizard, might also play an important role as he is often involved in Camelot's affairs.
Chapter 74, "Ordinary People", is the clearest early answer because it turns Lei Ting's situation into a concrete plot event. The chapter turns that into something concrete by moving from Having seen Jiang Li's ID before, he knew that this person named...
Chapter 350, "The Male Lead Actually Came Out to Clear Jiang Li's Name?!", is the clearest early answer because it turns Weibo's situation into a concrete plot event. It opens with The criticism on Weibo continued to ferment.
Chapter 335, "Songyang Ridge, Seven Houses Surrender, First Batch of Silver Arrives", is the clearest early answer because it pushes Li Longkai into a new phase or setting. A useful checkpoint is the way the scene starts with The wide and spacious main avenue, the various precious trees... and follows through with The tall building of the West District's jurisdiction was located on....
Chapter 243, "How Could It Be Her?!", is the clearest early answer because it turns Jiang Yan's situation into a concrete plot event. The chapter turns that into something concrete by moving from Hahaha, the young master's face has gone white, but I got a scare...
Chapter 20, "Miss Su, your defense is somewhat clumsy", is the clearest early answer because it turns Miss Su's situation into a concrete plot event. The chapter gives readers a real answer by opening on Several people turned their heads upon hearing the sound and saw...
Chapter 125, "The Great Seed Selection Contest!", is the clearest early answer because it turns Director Sun's situation into a concrete plot event. The chapter gives readers a real answer by opening on Next, it was Qi Tianyu's turn.
Chapter 344, "Actually has one million fans?!", is the clearest early answer because it turns Jiang Shixu's situation into a concrete plot event. The chapter turns that into something concrete by moving from Just as he was about to slip into sweet slumber and catch up on some...
Chapter 80, "Princess Wen, Your Lunch is Escaping!", is the clearest early answer because it turns Shu Yan's situation into a concrete plot event. Early on, Jiang Yan and Wen Jiaojiao, one so smug he was almost ascending to....
Chapter 65, "Jiang Li Missing?!", is the clearest early answer because it turns Miss Jiang's situation into a concrete plot event. A useful checkpoint is the way the scene starts with Several minutes later, the room remained silent.
Chapter 261, "They've Ruined the Entertainment Industry!", is the clearest early answer because it turns Weibo's situation into a concrete plot event. A useful checkpoint is the way the scene starts with The village chief's eyes nearly popped out after he heard the whole...