One more theme could be the exploration of human nature. The apocalypse brings out the best and worst in people. The 'op mc' gets to see the greed, the kindness, the betrayal, and the loyalty of those around them. It makes for a rich and complex story. Also, there's the theme of hope. Despite all the doom and gloom, the 'op mc' can be a symbol of hope, either for a small group or for the entire world in the light novel.
Rebuilding society can also be a theme. Even though the world is in chaos, the 'op mc' may have the ability and the will to start building something new. There is often a sense of adventure as well. The main character goes on quests, discovers new places, and uncovers secrets in the apocalyptic landscape. And there's the theme of morality. In a world where the rules have changed, the 'op mc' has to decide what is right and wrong.
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.
Another common theme is the fish - out - of - water situation. The MC is transported to a new world, so they have to adapt to new cultures, magic systems, and social structures. In 'Konosuba', Kazuma has to deal with all the crazy things in the isekai world while trying to make the best of his situation with his OP party members. And they often have a goal, like saving the new world or finding a way back home, which drives the story forward.
One such light novel could be 'Sword Art Online'. The main character Kirito is extremely powerful and often overcomes difficult challenges with ease.
One great aspect is the character growth. Despite being overpowered at the start, the main character can still face challenges that force them to develop further. Maybe they start out only using their physical strength but later learn to use their wits more. Also, the world - building in these light novels is often quite immersive. You get to see how the apocalyptic world is divided, what kind of new cultures or groups emerge, and how the 'op mc' navigates through all these complex situations.
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 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.
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 concept of starting anew with knowledge from a past life is always appealing. For an OP MC, it means they can often use their previous knowledge to gain an edge. For instance, if they were a gamer in their past life and are reincarnated into a game - like world, they can quickly understand the rules and power - up systems. It's like having a cheat code.
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 theme of harem or multiple relationships also exists in some 'op isekai light novel'. The OP male protagonist often attracts female characters. In 'In Another World With My Smartphone', the main character has multiple female companions around him. This adds a romantic or relationship - based sub - plot to the overall story of the isekai adventure and power growth.