Through Grisha's memory that he inherited through the Titans' powers, Eren saw Future Eren's plan. Effectively, when Season-3-Eren kissed Historia's hand, he saw his entire future, which included the declaration of war in Marley, The Rumbling, and his death at Mikasa Ackerman's hands.
Why did Eren see memories when he touched Historia?
When Eren came into physical contact with Historia in the awards scene, Historia's royal blood activated the attack titan's power for a brief period, which allowed Eren to see into his father's memories.
Unbeknownst to anyone, including Eren himself, the contact with Dina Fritz - a Titan with royal blood - causes Eren to briefly activate the power of the Coordinate in the Founding Titan. The surrounding Pure Titans, sensing Eren's desire/unknowing command for her death, attack the Smiling Titan.
Most believed it was the farmer as the Military Police stated, meanwhile the other half believed Eren Jaeger was the father. However, in Chapter 139 the theory was debunked and the Farmer was confirmed the father of Historia's baby.
In the beginning, Eren and Historia didn't have a lot of interaction until Eren was abducted by Rod Reiss in season 3. From there, he learns that it was his father who killed Historia's family, and out of guilt, asks her to go through with turning into a Titan and eating him, as instructed by her father.
English dub eren explains what happens when he touches Historia
What did Eren see after kissing Historia?
Eren's dramatic change in character came about after he kissed Historia's hand and saw the future, including a version of himself committing mass murder. All Titan Shifters in Attack on Titan have the ability to see the memories of those who held their Titan before them.
Fans speculate on the father of Historia's child: some believe it is the unnamed farmer, while others think it is Eren Yeager. The anime and manga provide evidence that supports the farmer as the father, as Historia is shown in a seemingly ordinary relationship with him.
Floch was entrusted to guard Historia. By telling Floch and Historia his plans, Eren was able to spread word of his intentions. By impregnating Historia, he would protect her and eradicate the Curse of Ymir. These events took place approximately ten months ago, the pregnancy period for Japanese women.
In AOTNR, Historia agrees to keep quiet about Eren's plan, but not for ambiguous reasons like in the original story, but only after Eren promises to come back alive to Paradis. In this version, Eren and Historia do have a romantic relationship and he becomes the father of her child.
At the Animagic 2014 series panel, producer George Wada confirmed that Ymir and Historia are "indeed a couple", which confirms that Historia in fact has romantic feelings for Ymir.
When Eren kissed Historia's hand after the Colossal, Armored, and Beast Titan were defeated within the island of Paradis, her bloodline as a part of the Royal Reiss Family activated an ability within the young Jaeger, allowing him to see everything that ever happened, or will happen, in his life.
With regards to Historia, Eren didn't want to put her or her child at risk in any way. Plus it wouldn't have worked with historia. The person eren comes into contact with has to be both of royal blood and a Titan. Historia isn't a pure or intelligent Titan.
Activating the Coordinate ability, a power that he did not know that he had, Eren seemingly started to gain control over the surrounding Titans and they proceeded to kill the Smiling Titan.
Armin claimed he "killed" Eren to conceal Mikasa taking Eren's head and to ensure a strategic move. This cover-up helped preserve peace in negotiations and involved Armin as the Scouts' leader in potential peace talks.
Witnessing his mother's death was traumatic enough, but seeing countless allies die in front of him was a major factor in Eren's fall to the dark side.
Eren's true feelings for Mikasa are finally revealed in the series finale, confirming that he is indeed in love with her. Their relationship has been inseparable since they were children, with Mikasa always being there to protect and support Eren.
Eren is not in love with Historia. It is true that he cares a lot about her, but no evidence as of right now suggests that he is in love with her. Eren's feelings for her are not portrayed as romantic and the same goes for Historia. She is not in love with Eren, although she greatly admires and respects him.
Why did Eren make that face when he kissed Historia?
Through Grisha's memory that he inherited through the Titans' powers, Eren saw Future Eren's plan. Effectively, when Season-3-Eren kissed Historia's hand, he saw his entire future, which included the declaration of war in Marley, The Rumbling, and his death at Mikasa Ackerman's hands.
Historia and the Farmer have known each other since they were children. He would bully her and throw rocks at her to gain her attention. Many years later out of guilt he worked in her orphanage in secret until Historia approached him in order to have a baby, later the two have a daughter and are now married.
Historia Reiss - She carried deep resentment towards her daughter. This was mostly out of fear of being executed by order of the council for "shaming" Rod and his reputation by birthing his illegitimate child and being his mistress.
No Mikasa and Eren didn't have any kids, The mikasa ending in the story was quite mysterious because isayama obviously wanted the people to focus on the message behind the ending and humanity's future and not things like who married who didn't. The story starts with 3 young children but ends with the world's destiny.
Despite the dissimilar natures of Ymir and Historia, it was these exact conflicting traits that drew them together and which made them fall in love with one another.
Eren has the founding, he can't use it cause he's not royal. Historia is, but it only fully works if Historia is a titan… HENCE why it works when eren is near Dina Fritz OR Zeke Fritz/yaeger. They don't trust Zeke, so their plan is instead to have Historia eat Zeke so they can use Eren's powers.
