The antagonist is often very interesting. In Assassin Reborn, the antagonist might be someone from the assassin's past who has also changed or someone who is threatened by the assassin's new - found power. Their motives and methods of trying to stop the protagonist can be full of twists and turns, making them a character to watch out for.
I think the main protagonist is often one of the most interesting characters. Their journey and development usually form the core of the story.
The slime protagonist is quite interesting. His transformation from a human to a slime and his unique growth process make him stand out.
The titular greatest demon lord is definitely one of the most interesting. His journey from being a powerful and feared figure to being reborn and having to adapt is captivating.
Ezio Auditore is quite interesting. He's a skilled Assassin who has to navigate the complex politics and power struggles of the Renaissance in Italy. His character development from a young nobleman to a master Assassin is captivating.
The protagonist is surely one of the most interesting characters. As an extra reborn, they have a unique perspective on the world. They might have memories of their previous life which makes their actions and decisions different from the regular extras in the story. Also, any character who helps or hinders the protagonist's journey can be interesting. For example, a mentor - like figure who guides the protagonist in this new world, or an antagonist who tries to keep the protagonist in the 'extra' status.
Perhaps the people who interact with the reborn demon lord are interesting too. They might be ordinary folks who are unaware of his past. Their reactions to him and how they influence his new life could be very engaging. For example, a kind - hearted neighbor who befriends him without knowing his true origin.
Battler is quite interesting. His determination to solve the mysteries on the island makes him a central figure. Also, Beatrice is fascinating with her mysterious nature.
Geralt is definitely one of the most interesting. His complex personality, being a Witcher with a sense of honor but also a loner, makes him stand out. Yennefer is also fascinating. Her powerful magic and her tempestuous relationship with Geralt add a lot of drama. And Ciri, with her special abilities and her role in the prophecy, is a really engaging character.
I think Tatsuya Shiba is one of the most interesting characters. He is not only highly intelligent but also has a special kind of magic that is different from the norm. His character development from being underestimated to becoming a key figure is great. Another interesting character is Erika Chiba. She has a tomboyish charm and her own set of skills in combat magic, which adds a lot of flavor to the story.
Haruhiro is quite interesting. He starts off as a rather ordinary and indecisive person but gradually grows into a more confident leader. Then there's Yume. Her cheerful and energetic personality stands out in the group.