Characters that ruined a game for you? Ever reached the point of stopping playing because of a character?

Intrigued by this post description of Ys: Lacrimosa of Dana; action adventure JRPG? sign me up, just what I wanted to play!
The Episode 0, where you learn the basics and control the main character was nice, the first fight, with a boss was fantastic, the game geared up to be a great experience.
Conversations with NPCs seemed the usual JRPG fare, but they were ok, characters looked nice, nothing to write home about, but it drew you in into the story well enough.

The problem started when Episode 1 presented you with Laxia, a classical "Tsundere" type of character, where every dialogue option was answered with demeaning, hostile intent against the character. Everything about this character made me want to leave it right where I found her, after reading a bit online and finding she is a Main character and that it never gets better I dropped the game for now. I don't play to be belittled by a teen. It didn't help that the game played up some very dumb tropes, like the accidental pervert and stuff, I know, It's a silly ARPG, not a profound introspection on human nature...

The point I'm going is that, by putting such a disagreeable character right at the beginning burned out my desire to know about the game world, it was tainted by the grating presence of that character.
So I dropped it for now. But it got me thinking, people sometimes loathe escort characters that you have to protect, or characters that are forced onto the player and make the game experience worse.
Skyward Sword's Fi comes to mind, going so far as to mod the game to make the character less annoying.

So, any characters that made your game experience actively worse? Any that was so terrible that made you drop a game, either temporally or permanently?