One great Chinese light novel with a powerful main character (MC) is 'Martial World'. The MC in this novel has an amazing journey of growth in the martial arts world. He overcomes numerous challenges and his character development is really interesting.
Power progression is a common theme. The OP main character usually starts from a certain level of strength and becomes even more powerful over time. Another is the development of relationships with multiple female characters. They often start with misunderstandings or the main character helping the females in some way, and then relationships grow.
They usually have a growth arc, even if they start out OP. Take some of the MCs in light novels like 'Log Horizon'. Shiroe, while already having strong gaming knowledge and skills, still grows in terms of his leadership and understanding of the new world he is in. This growth makes them more relatable and interesting, despite their overpowered nature.
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.
Sure. 'Overlord' is a great one. The main character is extremely overpowered as he gets transported to a new world. He has incredible strength and abilities from the start which makes his adventures in the isekai world very interesting.
Sure. 'Date A Live' is a great 'op mc harem light novel'. Shido Itsuka has the ability to seal the powers of the Spirits, which are powerful female entities. He ends up in a harem - like situation as he tries to save the Spirits. Also, 'High School DxD' features Issei Hyoudou, an OP main character who is surrounded by a bevy of beautiful female devils and angels, making it a typical harem light novel.
One popular OP (Overpowered) MC (Main Character) Asian light novel is 'Sword Art Online'. The main character, Kirito, is extremely powerful and his adventures in the virtual world of SAO are full of action and drama. Another is 'Overlord'. In this novel, the MC Momonga is a very powerful sorcerer who gets trapped in a game world and has to navigate through various challenges with his overwhelming power.
I think 'That Time I Got Reincarnated as a Slime' is also a top OP MC light novel. Rimuru Tempest, the slime, gains many powers and abilities as he progresses. He starts from being a weak slime but quickly becomes very powerful, with skills like 'Predator' which allows him to absorb other beings and gain their powers. It's really interesting to see how he uses his OP abilities to build his own nation.
Well, first of all, a strong character arc for the MC. If the MC starts from being weak and gradually becomes OP in a believable way, it's really appealing. For example, in some novels, the MC has to endure hardships and learn from his experiences to gain power.