I Became the Dark Knight in the Game게임 속 흑기사가 되었다

dunno where you saw the witcher similarities besides the white hair

I can see the similarity between him and Geralt.
They are out of the norm even for their professions and both seek to do good in their own way even if it isn't what they are meant to be or do.
What people say about them doesn't affect them that much.
They are both more or less annoyed how humans can be more inhuman than them but they have gotten used to it at some point.
They go out of their way to help people but always deny it as them proving something to themselves like the tsun they are...
But saying other characters are also inspired by it might be a stretch considering these kinds of characters are a good setting for a story like this.
But who knows maybe the author is a fan and took inspiration nonetheless.

They are usually just sent to a parallel universe with the setting of the items you mentioned, if not, the author/creator is an eldritch being who sent them there.

I think that's part of the mystery isn't it how they got here. And it's never really a game they got into. It's always like the game was based on reality rather then the other way around

while crying at the same time

Cashier: Mam, this is a Wendys.

***martha!*** on the inside