Well, 'The Saint's Magic Power is Omnipotent' has a somewhat similar feel. In this novel, the main character has her own charm and the story unfolds in a way that is similar to the discovery of hidden qualities in 'My Husband Hides His Beauty'. Also, 'Snow White with the Red Hair' where the characters have their own allure and the relationship development is engaging.
One similar light novel could be 'My Next Life as a Villainess: All Routes Lead to Doom!'. It also has elements of unique character relationships and interesting plot twists. Another one is 'Kiss Him, Not Me', which shares the aspect of dealing with complex feelings towards a particular character.
Love and acceptance could be another theme. Despite the husband hiding his beauty, the relationship between him and his partner might still develop based on true love and acceptance of each other's true selves. This shows that love can be more than just physical attraction.
One similar novel could be 'The Secret Husband'. It also has elements of mystery surrounding the male lead.
There is also 'The Beauty's Secret' light novel. In this one, the main character, a beauty, has a mysterious side to her. It delves into her relationships and how her beauty affects those around her, just like what might be expected in a light novel with 'beauty' in the title.
Another example is 'Sword Art Online'. Kirito often hides his full capabilities in the game world. He doesn't always show his best skills and strength, especially when he wants to avoid unwanted attention or when he is trying to figure out the motives of other players. He only reveals his true strength when it's absolutely necessary, like when facing powerful bosses or protecting his friends.
One popular one is 'Solo Leveling'. The main character, Sung Jin - Woo, initially appears weak but gradually reveals his incredible strength. Another is 'Overlord', where the protagonist Momonga hides his true power in the new world he is transported to. And 'The Rising of the Shield Hero' also has a main character, Naofumi Iwatani, who is underestimated at first and hides his growing capabilities.
One similar light novel could be 'Sword Art Online'. It also has a lot of adventure elements in a virtual world like 'my dungeon light novel'. Another one is 'Log Horizon' which features characters exploring and dealing with various situations in a game - like world. There's also 'Overlord' where the main character has to navigate through a strange new world which has some similarities in terms of the exploration aspect.
I'm not very familiar with a specific 'You are my regret light novel'. But some popular light novels in general are 'Sword Art Online' and 'Re:Zero − Starting Life in Another World'. They have engaging storylines and well - developed characters.
Well, 'My Husband in Name Only Novel' might be unique in its own way, but there are novels with related concepts. For example, 'A Pretend Marriage' which explores the idea of a couple being married just for appearance or some external reasons at the start. Also, 'The Marriage Contract' has a plot where the marriage is more of a formality initially and then things start to change. There's also 'The Sham Marriage' which is about a marriage that has more to it than just the name.
Well, 'Rascal Does Not Dream of Bunny Girl Senpai' can be considered. It deals with various issues within a school setting and has complex character relationships. 'KonoSuba' is also a great choice. It's a comical take on a fantasy world but has elements that can be related to the idea of protecting or being around someone like in the 'school beauty's personal bodyguard' concept. Additionally, 'Date A Live' with its unique plot about saving girls has some similarities in terms of the male lead's role which can be somewhat like a bodyguard in certain situations.
One similar light novel could be 'My Girlfriend is a Shaman'. It has a similar concept of having an extraordinary relationship with a female lead in an interesting setting.