I strongly disagree with this.
Eren's character has been so mishandled it's fucking mindboggling. He literally has every right to be what he current is, and yet no one fucking focuses on it. He's a bloodthirsty violent lunatic who traumatized and used for his entire life, and instead of focusing on that and have his entire current character be foreshadowed for the entire series, AoT decides to focus on racism, and bigotry that's foundation is so fucking convoluted, and over-the-top it makes the racism and bigotry in Code Geass look non-existent as the reason he's like this, and act like he was never fucked up in the first place.
This arc at one point kind of tried to briefly fix this (I think) with the flashback of his mom getting eaten, but it doesn't mention all the other shit he went through and has fucking done. And to top it all off, his edgelord mentality makes him feel like a whiny brat when again, it should make perfect sense.
I've said this many times, but Genocidal!Eren isn't a bad concept at all, and when you look at his entire character, makes sense. It's literally everything around it, and the motivations given for it that make it not work.
I mean, if I went with this storyline for AoT (and I wouldn't, since I don't have a boner for the Nazis are the real Jews), the entire motivation for Eren would be focused on abuse. That his feelings were mishandled from the beginning and he was only seen as a weapon. Maybe he thought he was part of the scouts and Erwin said that to him, but maybe after one event Erwin snaps and a moment of anger tells him he's their weapon to use. Slowly break down that foundation of idolization.
Realize they care more about his use as a machine than a person. Make his friends flippant about this, saying its for the greater good. Have Levi be incredibly abusive for it. Make him blame Eren for Petra's death when it wasn't his fault. Make Mikasa only want to protect him, but incapable of dealing with him emotionally. Make her fuck up noticing the signs.
Then, at the return to Shiganshina, he just fucking breaks. He realizes everything was just a sham for some bullshit some assholes did centuries before any of them were even born. He's a weapon? So he becomes one. He becomes the fucking wrath of God. That is his goal. He doesn't consider it a genocide, he considers it natural, because that is what he was made for. He'd compare it to earthquakes or floods or mudslides.
He just suffers a total psychotic break. "Genocide? No. A gun does not care about the person its bullet hits. A sword doesn't think about the person it cuts down. I am a weapon. Old and young, man and woman. Weapons do not discriminate. Their motivations are pure and honest: To destroy the enemy. I am doing what is natural to me."
He'd be suffering from Dissociative Disorder, in that, all that abuse and telling him he wasn't human, he'd feel disconnected from his body. And that disconnect causes him to lose his sense of self and his mind, only to fully embrace the horror that they wanted. Eren should be framed as a consequence of their desires. They wanted him to be a weapon, an engine of destruction, so he become one in complete form and function. There's no negotiation anymore. No redemption. He's completely lost, and there is no coming back for him.
Not to mention his plans completely come to fruition. Have him dispassionately murder his friends one by one, until Mikasa is the only one left. Eren wins completely. Everything is destroyed and the death toll is beyond counting. When she finds Eren, all he says to her is: "When a weapon is done, it must be sheathed." And he kills himself. Mikasa is the horrified, lone survivor.
Of course, it is an interesting road to go down, you reap what you sow. The problem is that the scouts aren't framed as abusive and Eren's abuse is basically ignored, so the whole thing is completely fucked.
