Saying there's no villain in Attack on Titan doesn't mean individual actions can't be seen/perceived as "good" or "bad". That's where perspective plays a major key role. Is just that judging the characters in a vacuum, or solely under our own moral scope totally misses the point.

These characters are humans thrown into the hell of the world, dealing with a reality far more extreme and cruel than us readers and the series does a heck of a job in exploring their inner conflict while presenting relatable themes such as war, discrimination, and fear.

They all are part of a conflict they never wished to be part of in the first place. Yet, all of them have reason to keep moving forward. No one wakes up one day and decides to be a "bad person" for the sake of it, everything makes sense when you place yourself in their shoes.

In short: If the concept of "morally grey" annoys you so badly, then maybe AoT isn't the story for you. Not every piece of fiction has to deal in absolutes.

I would like to clarify that this thread wasn't against the people who choose to call Eren a villain, but more against the notion that he's 100% a villain and the people who don't see it that way are 100% in the wrong.

To me, there are no villains in AoT. But if someone wants to call Eren a villain, that's their PoV. If we go by the definition, it's hard for me to place Eren in an exclusive category since there are many layers to his actions and he plays different roles throughout the story.