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 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.
It might involve showing genuine understanding and support. Maybe there's a specific event or challenge in that chapter that you can use to your advantage to connect with him.
Well, you could try doing things he likes together to strengthen the bond. Also, showing appreciation and support for him can go a long way. Sometimes, small gestures of love and care can make a big difference.
One way could be to have heart-to-heart conversations regularly, listen to his perspective, and work on resolving any conflicts together. Surprising him with small gestures of love and support might also make a difference.