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.
One great light novel with a powerful main character (MC) is 'Overlord'. The MC, Ainz Ooal Gown, is extremely OP (overpowered). He starts as a max - level character in a game world that has suddenly become a reality. His abilities and strategic mind make him nearly unbeatable.
The harem aspect means there are multiple female characters who are attracted to the MC. In these manga, the relationships can range from simple admiration to deeper emotional bonds. The female characters often have diverse personalities and abilities, adding to the complexity of the story. For instance, in 'Death March to the Parallel World Rhapsody', the harem members include a princess, an elf, etc.
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 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.
'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.
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.
There's also 'Death March to the Parallel World Rhapsody'. The MC Ichirou Suzuki is overpowered and gradually builds up a harem of various characters in the isekai setting. The story has a mix of adventure, comedy and some harem elements.
One great OP MC (Overpowered Main Character) fantasy light novel is 'Sword Art Online'. The main character, Kirito, is extremely skilled and powerful in the virtual world of Aincrad. Another is 'Overlord'. Momonga, the main character, is a very powerful magic caster in a game world that has become a reality. Also, 'That Time I Got Reincarnated as a Slime' is good. Rimuru starts as a slime but quickly gains incredible powers and builds his own nation.
The light novel 'Akame ga Kill!' also has an OP female MC in Akame. She is a highly trained assassin with a powerful teigu (a special weapon). Her skills in combat and stealth are top - notch, allowing her to take on much stronger opponents.