A common feature is character growth. The protagonist, having a second chance, uses the leveling system to become more powerful, like in 'The Legendary Mechanic'. Another is the exploration of new opportunities. Since it's a second chance, they can make different choices and explore areas or relationships they missed before. For example, in 'Solo Leveling', the character can now take on quests he previously couldn't.
Well, 'Overlord' can also be considered in a way. The main character is transported to another world and has to use his knowledge and a sort of leveling system within that world. He gets a second chance at power and domination in this new realm. The novel is known for its detailed world - building and complex characters, and the leveling system adds an exciting aspect to the story as we see the protagonist's power grow over time.
Well, it varies. In 'Re:Zero − Starting Life in Another World', Subaru levels up his skills based on his repeated experiences. Every time he dies and restarts, he can learn from his past mistakes and grow in terms of abilities. In 'The Rising of the Shield Hero', the shield hero levels up by fighting enemies and also by finding and using rare items. His shield evolves as he levels up, which gives him new powers. In 'Log Horizon', the leveling system is based on the game mechanics they are familiar with, but with some twists due to being trapped in the game world. They level up by completing quests, fighting mobs, and learning new skills within the game world.
Well, in many such novels, it often involves defeating enemies. For example, in 'Solo Leveling', the protagonist gets experience points from killing monsters in dungeons. Each kill or completion of a dungeon level gives him points to level up his stats like strength, speed, etc.
It usually has unique rewards. In 'Overlord', as the main character levels up, he gains not only more power but also access to unique items and abilities that are specific to his class and level. These rewards help to distinguish his character and make the leveling more appealing.
Challenges or quests are also common. Characters need to complete tasks or overcome enemies to level up. In 'Overlord', the main character has to deal with various threats in the game - turned - real - world, and by doing so, he levels up and expands his territory. This adds a sense of adventure and purpose to the story.
In many 'super leveling system novel', it often works by the character achieving certain goals like defeating enemies. For example, in 'Solo Leveling', the main character gets experience points from hunting monsters, and as he accumulates enough points, he levels up and gains new abilities.
Well, 'The Rising of the Shield Hero' is a great leveling system light novel. The shield hero has to level up his skills and abilities in a rather unfair world. He has to figure out how to use his shield in different ways to grow stronger. Then there's 'Log Horizon', which focuses on a group of players trapped in a game world and they have to use the leveling system within the game to not only survive but also to understand the new rules of this virtual world. Also, 'DanMachi' has a leveling system where the characters explore a dungeon and level up based on their achievements in the dungeon.
Another good one is 'Overlord'. The main character, Momonga, is transferred to a new world with his guild's base and all its NPCs. His leveling system is complex and intertwined with his ability to rule over his territory and deal with various threats. The way he levels up his minions and himself makes for a very engaging read.
I recommend the following novels to you: The Strongest Cultivation Upgrade System and The Supreme Upgrade System. These two novels were both fantasy and oriental fantasy. The main characters had a super powerful leveling system that could continuously improve their strength in the process of fighting monsters. Among them, the Strongest Cultivation Upgrade System also had the All-rounded Strongest System Mode, which allowed one to obtain all kinds of magical equipment, medicinal pills, and cultivation techniques. If you like the plot of leveling up and fighting monsters, you might as well read these two novels. I hope you like my recommendation. Muah ~