Board Thread:Manga/@comment-26624146-20170826063316/@comment-27125793-20171009160702

I don't think there are any real heroes or villains in Attack On Titan. Protagonists and antagonists, sure, but the villain/hero labels imply moral connotations, but it's not morally straightforward. I believe the reason for Isayama's large amounts of flashbacks and exposition was exactly to prove this point; that all characters and entities are shaped by their expeiences and that many of their cruel actions aren't without unreasonable motives. Even Marley's mistreatment of Eldians isn't completely unjustified, since Eldia had oppressed it and most of the other nations for over a thousand years, and they even treat the Eldians better than the other nations do, as Udo had revealed.

Zeke is a soldier, who was raised to believe that all from Paradis are "devils", so the ease with which he kills them is reasonable. Even if he doesn't buy into the Marleyan propaganda, the people of Paradis were still his enemies. As for his sadistic tendencies, let's not forget Levi and Hange. They had taken enjoyment in torturing Djel Sannes without even asking him any questions, and these are among the main protagonists. If you try to use Nick's torture as justification for their actions, please search the term Moral Myopia in the TV Tropes website. Isayama, unlike many other manga authors, imbued the 'heroes' with personality aspects we as readers aren't exactly comfortable with, for he's trying to be as realistic as possible, and in the real world, both sides in a conflict have good and evil in them. The 'heroes' can be self-righteous, hypocritical and intensely selfish too.

Ultimately, I don't think Zeke is a villain, let alone the main villain, but there is always a possibility he could be the main antagonist. We'll just have to wait and see.