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This thread will debunk: "Historia has no development post timeskip and her only purpose is to bear a child for Eren's plan". Feel free to send it to whoever think they're smart by saying that.
Historia is known for her amazing development in the Uprising arc, where she started to make of herself a priority and make the choices she wanted to make. Leaving behind her Christa self, that would do anything for others and would sacrifice herself to not die in vain. 1/11
I won't go in depth about her character pre-timeskip, I have made a post on reddit about her Mikasa and Armin so feel free to read it if you want to know how I interpret her character to be. People tend to say her character is done 2/11 https://www.reddit.com/r/titanfolk/comments/i6lc1o/armin_historia_and_mikasa_their_relationship_with/?utm_medium=android_app&utm_source=share
People that say that often think screentime = importance. It can be true but it isn't in Historia's case. Historia was first of all the only one Eren told his real plan to only because he trusted her. See, Eren trusts Floch, but Eren had benefit in telling his plan to him 3/11
In Historia's case, Eren did not want her to do anything for him, just to be safe and to know what he is about to do. Historia could've make his real plan fail anythime. She had all the power to do it, wanted to do it and also directly told Eren she wanted to. 4/11
But she then remembered, thanks to Eren, she needed to make herself and her people a priority, thus she chose to trust Eren. She once again threw all her humanity away to make her own choice: let mankind get destroyed by titans and choose Eren, Parasis and her futur family 5/11
Thanks to her, Eren is now able to continue with his plan. But Historia knows genocide is irredeemable, and she also knows Eren is aware of that. So she gave a reason for Eren to go on with his plan, and go through hell to see what is beyond it. 6/11
So, Historia asked Eren what he would think about her bearing a child. If it's Eren's or not doesn't mean much in this context, but her child is a motivation for Eren to move forward. Eren doesn't want royal blooded children to become a tool for anyone. 7/11
He doesn't want the cycle to continue. So, her child made Eren's must of protecting his island and friends, become his will. He doesn't WANT her to become a titan and her children to eat her and become titans as well, so he keeps moving forward. 8/11
On top of it, she asked to bear a child herself, so she most definitely chose someone she loved to do it. That would also mean that it would be the first royal blooded child born out of love and not as a reward or to become a shifter. That is already a huge step forward. 9/11
Her child is not only a motivation for Eren, but also a representation of a new world full of freedom. Where her child doesn't have to live oppressed and become a titan. The 2000 year cycle will then be broken, and their goal will most likely succeed. 10/11
In conclusion what makes her important is not her actions but what she means to the PLOT of the story. Without her post timeskip, a lot of things wouldn't make a lot of sense so saying she became useless is the dumbest statement you can make about the AoT manga. 11/11
Everything I said in this thread are conclusions I made reading the manga a second time concentrating on Historia's character. And I am convinced that anyone who would read it again would come to the same conclusion. Feel free to tell me if you think I forgot anything.
I would also like to debate with anyone that has valid and interesting points that can prove me wrong without bringing up other character. But thank you for reading it all. Here's a picture of this perfect human being to thank you 
