It's hard to say without reading the whole novel, but often the main character in a harem - style story is quite interesting. They have to deal with multiple relationships at once. Maybe there's a character who is very mysterious and has some hidden powers or motives, which makes them stand out.
Perhaps the main human protagonist is the most interesting. He could be someone who has a special connection with the gods, like being a chosen one. His journey of discovery and how he copes with the godly interventions in his life would make him an engaging character.
Definitely Hori. She has to balance her school life, where she is popular and responsible, with her home life where she takes care of her younger brother. Her relationship with Miyamura also shows different aspects of her personality. And Miyamura, with his past that he has kept hidden from most people, is very interesting. As the story progresses, we see him open up more and more, which is a great character arc.
Naruto Uzumaki himself is very interesting. His never - give - up attitude and his journey from an outcast in the village to a hero is inspiring. He has a unique power within him, the Nine - Tails, which adds to his complexity.
The protagonist is quite interesting. His desire to be a power in the shadows while often getting caught up in unexpected situations makes him stand out. Also, the side characters who interact with him and either help or hinder his plans add depth to the story.
Denji is really interesting. His simple desires like wanting to touch boobs at the start, and then his growth as he gets more involved in the complex world of devil hunting make him stand out. Then there's Power. She is a fiesty and unpredictable character with her own set of motives and a unique power set.
The Goblin Slayer himself is quite interesting. His single - minded focus on killing goblins and his rather stoic personality make him stand out. Then there's Priestess. Her growth from a novice to a more confident adventurer is engaging.
Hermione Granger is really interesting. She's super smart and always has the answers in class. She also has a strong sense of justice. Sirius Black is also fascinating. He's a complex character with a troubled past and a fierce loyalty to Harry.
Ayanokoji Kiyotaka is really interesting. He seems quiet and unassuming at first, but he has a very sharp mind and is always calculating things behind the scenes.
Fran is one of the most interesting characters without a doubt. Her naivete combined with her fierce determination makes her stand out. The blacksmith in the story is also quite interesting. He helps the sword upgrade and his interactions with Fran and the sword are full of character.
Rimuru is definitely one of the most interesting. His transformation from a simple slime to a complex and powerful leader is fascinating. Then there's Shuna. Her loyalty to Rimuru and her skills in cooking and management make her stand out.