Another common main character type is the damsel in distress. Like Guinevere. She was King Arthur's queen. Her character often added a romantic and sometimes conflict - inducing element to the story as she was the object of many knights' affections.
One popular main character is Beowulf. He is a hero from the Anglo - Saxon epic. Beowulf is known for his great strength and courage. He battles fearsome monsters like Grendel and his mother, and later a dragon. His character embodies the values of the time, such as heroism and loyalty.
OP main characters can also attract a large fan base. Fans love to see these powerful characters dominate in battles. In 'Sword Art Online', Kirito's OP skills make him a very popular character, and his actions are central to the story's development, especially when he takes on the toughest bosses.
Obviously Naruto would be one of the main characters. Since it's set in an academy, his classmates like Sasuke and Sakura would likely also be important characters. The academy teachers, such as Iruka - sensei, would probably play significant roles as well.
Typically, they are often very powerful from the get - go. For example, in 'Overlord', the main character has a vast array of powerful spells and an army at his disposal right after being transported to the new world. This immediate power gives them an edge in the new and often dangerous isekai settings.
One of the most OP characters is Superman from DC Comics. He has super strength, can fly, has heat vision, and is nearly invulnerable. His powers make him extremely difficult to defeat in most situations.
Chivalry is a very common theme. Knights are expected to be brave, honorable, and protect the weak. Another theme is the feudal system, with lords, vassals, and peasants. Love and courtship also play a big role, often in a very formal and chaste way in the medieval context.
'The Beginning After The End' is also a top - notch OP MC novel. Arthur Leywin is reincarnated into a world with magic and he has an innate talent that allows him to quickly rise in power. The story not only focuses on his power growth but also on his relationships and the world - building is quite immersive.
One popular one is 'Overlord'. The main character Momonga is extremely OP. He is transported into a game world where he has incredible power and has to navigate this new reality.