Let me tell you about Yuya Tenjo from I Got a Cheat Skill in Another World and Became Unrivaled in the Real World, Too… nah that would be too easy a target. Low-hanging fruit, same as with Rudeus or Naofumi, but I could certainly do without those characters.

No, I chose Fuuga Haan from How a Realist Hero Rebuilt the Kingdom. That character’s story spans the entire last arc (or the last two depending on how you’re counting) and killed the entire series for me. It’s one thing to have a unlikeable character in the series but it’s an entirely different story when the main focus shifts to that character for 10 volumes or so. And I think the character could have worked if the author had shown ~90% less of him. With what is written in the pages there is a distinct disconnect between what we see of him and how he is described both on-page and in-universe. Imagine the prose and the characters describing an illustrious and ascended warrior the likes of which can only be seen every thousand years, with charisma that could rival the Gods and launch a thousand ships. And then you turn around and look at some drooling idiot flopping around on the floor like a fish out of water and laughing about the smell of his own feet. And while he’s trying to bite his shadow you turn back around again and ask “You sure? That guy? Yeah, I don’t see it…”. And that’s basically how the final big chunk of Realist Hero goes. So, I definitely could do without that character.

Grea Asgeir from Rise of the Weakest Summoner. She starts out as this eccentric professor at the summoner academy and the only one who gives the titular character a chance, which is fine. What isn’t fine is when she devolves into a raging self-proclaimed slut even though she was a virgin before the MC and then tells everyone (including royalty) about how she’s riding dragon dick with the most foul-mouth and the most dialog of any character in the harem despite being like the the seventh one added. She then robs the life out of every other character by being so painstakingly over-the-top at all times.

Killed the series for me.