I don't see how Eren killing career human traffickers who brutally murdered someone's family in front of them and kidnapped that someone to sell them into sexual slavery means he's a monster at that point in the story, Can you say you wouldn't be as furious in that position, at that age? or made a naive attempt to save that person? he's damn lucky he was able to get out of that alive, and there was no other way than making sure the traffickers were dead. what was he gonna do, wait for the MPs? ask them nicely to let her go, or somehow restrain them? they had to die. that's about as close to morally justified killing as the series has. the world was genuinely a slightly better place without them. I think retroactively isayama wanted that to be foreshadowing, but trying to frame that event as comparable to killing innocent civilians later on and then trying to murder 99% of the human race just seems silly to me. at least thats what I feel he's going for.
It's not the fact that Eren killed them. He was completely right to do so. Those fuckers deserved to die, and then some.
It's the fact that he did so readily, angrily, and that he did it when he was fucking
eight. If he had done this when he was a teenager, I'd have no problem with it. But the fact is that Eren did it when he was a child. That fact that Eren at such a young age already had so much wrath inside him is what disturbs me.
Can I say I wouldn't be angry if I was in his position at his age? No, but I do know that my anger would be vastly outweighed by my terror. I'd be crying, and scared out of my mind. I wouldn't screaming about how "they were a disease", I'd be screaming because I would be terrified. If Eren killed them while acting like how I would, or rather, how any other child at his age would, as in tearfully shrieking in fear as I frantically stab them so they wouldn't hurt me, or my friend, I wouldn't have a problem with this at all. The disconnect occurs because Eren doesn't do that, and his behavior comes across as deeply unsettling, and unnatural.
Again, the issue is not that he kills them. He had every right to do it, and his actions were the right thing to do. He saved Mikasa. It's just how gun-ho, and for lack of a better word, insane, and bloodthirsty he is when he does it. Not to mention how he disturbingly lures the sex-traffickers into a false sense of security before stabbing one in the chest while coldly telling him he's not stupid, which just makes Eren seem even more unhinged.
There's a difference between a child forced to kill in self-defense, and a child forced to kill in self-defense who does it so calculatedly, and then starts screaming "YOU'RE A DISEASE! DIE! DIE!" as he brutally stabs a man over and over again. The two the are not the same situation.
I am not saying Eren was a monster at this time, and I apologize if that's what my words implied. What I meant was that he has always been crazy. He was not a monster, nor evil, but he was definitely not sane. Eren's actions during this scene by no means say that what has become was inevitable, but given the events of the the most recent chapters, they do come across as a very massive red flag.