For anyone whoās saying chapter 138 is a disservice to Erenās character; for anyone who think Erenās decision to live with Mikasa after a simple confession is ridiculous:
Eren was pitted against two choices: a) Let the world trample Paradis, or b) Wipe out the rest of the world. Choice a) is bad for his people, but at least innocent lives outside Paradis will be spared. Choice b) is good for his people, but so much innocent people will be lost.
Eren is in despair. He truly believes wiping out the rest of the world is the best course of action, but heās painfully aware that itās wrong. He finally understand why Reiner is such an half-assed bastard,Ā but he canāt say that since heās much worse than him; Reiner broke down the walls to save the world, while Eren is willing to do genocide because of his selfish desire to do so. The guilt is eating him alive.
At this lowest point of his life, Mikasa came.
He wondered why Mikasa always sticks to this good-for-nothing guy, whoās about to massacre the rest of the world. What did she see in him? Why did she choose him? Depending on her answer, he might stop. This is where Mikasaās confession plays a big role, because he was so tired of it all, heās hanging on to Mikasaās answer for dear life.Ā
Well, she ended up with this answer so he had to move on with his initial plan. But look, if youāre suffering this much, who wouldnāt want to run away? Especially with your loved ones?
If only she gave a different answer, heād run away with her, to a secluded place where no one can reach them, forget about it all, and live the rest of their lives in peace.
Of course, this is just what Eren wished in the spur of moment, just like Armin whoās so tired, he wished to sleep 2 days straight. The alternative timeline merely shows us what would Eren do if Mikasa gave him another answer; doesnāt necessarily mean heād be happy with it, or itād give a better outcome. Even if this alt. scenario happened, he still wouldnāt be able to live with himself due to greater regrets.
Paradis would be fucked up, he left Armin, Jean, and Connie to fight alone, he would disappoint Historia who already surrender herself to have a child -just to support Erenās plan; all the sacrifices in Liberio would be for nothing.
He thought itās selfish of him to fulfill his own desire and abandon his responsibility. Thatās why he chose the answer with the least regret: Genocide.
Even then, itās not like his regret disappeared.
He regrets putting the Scouts and his friends into danger,
He regrets killing innocent lives,
so much that he imagined himself as a child reaching for his dream, to cope with his trauma.
This is where Reiner comes into play, because heās the one who understand Erenās situation the most.
Eren will keep moving forward, until he eliminated all his enemies.Ā He will keep moving forward, until someone stops him, just like how it used to be.
TLDR; Eren is a complex character with a lot of layers. They say action speaks louder than words, but thatās not always the case. Sometimes, the unspeakable words IS the true feeling. Our action does not reflect our feeling or what we wished for. So no, chapter 138 is NOT a disservice on Erenās character.Ā
Eren mightāve grown past his childish rage and be more cold-hearted and calculative, but it also means he understood better of the gravity of his action. It doesnāt make it easier, it only makes him suffer. Thatās why it has to stop eventually, and I couldnāt ask for something better than chapter 138.