EreHisuFloch

EreHisuFloch is the poly ship between Eren Jaeger, Historia Reiss and Floch Forster from the Attack on Titan fandom.

Canon
Both Historia and Floch were the only ones who were aware of Eren's true plan, which was to bring ruins to the world with the Rumbling. Both Historia and Floch acted shocked with the plan that'll kill millions in the process. However, while Floch understood Eren's plan and supported it immediately, Historia cried out loud, urgently pleading Eren to not go ahead with the genocide, since she thought it was wrong. Historia told Eren to think about the people outside the walls who were just like his mother. Before learning about Eren's true plan, Floch overhears Yelena and him talking about Zeke's true plan. Zeke's plan consisted of the euthanizing of the Eldian race, so Eren tells Floch to pretend to follow Zeke so they can reach their true goal.

With the knowledge of Eren's true intention, the plan begins. Historia gets pregnant by a farmer, but Historia is currently in the process of giving birth. While Historia is pregnant, Floch begins to gather allies to help with Eren's plan. This group they formed ends up being known as the Yeagerists/Jaegerists. Floch is later killed by Mikasa and Eren is soon after beheaded by Mikasa, stopping the rumbling. In the final chapter it's revealed that the living Yeagerists have taken over Paradis as they went from a rebel group to an army, as Historia mentions.

Junior High Manga
With Floch and Historia having no direct interaction on the main story, except the fact the two were in the same class and Historia honoring both Floch and Eren for their bravery. But the two are shown interacting in Junior High Manga. Most of the time the two mangas have a sort of connection with each other as Junior High makes references to the main story. Both Floch and Historia stay back from entering Marley Academy, which is also the same in the main story as Floch did not attend the meeting with Kiyomi in Marley, so it's most likely that Eren asked Floch to stay of guard of Historia while Eren went to Marley with the other Survey Corps members.

Fanon
It's known among the fandom that the trio is somewhat 'cold' due to their drastic change in personality. There currently aren't written works on Archive of Our Own but there are fanarts of the trio.

However there are some theories that Eren must've sent Floch to tell Historia how the Military Police wanted to feed Zeke to Historia as soon as possible and told her to get pregnant immediately, but some believe Eren is the hooded person himself. Some fans joke that Floch is the father of Historia's baby.

The poly ship is mainly shipped by those who ship Eren and Historia. After the release of the Chapter 139, however, most fans abandoned this trio due to Eren's choice of going ahead with the Rumbling.

Fandom
 FAN FICTION 

Variations

 * EreHisu refers to the ship between Eren Jaeger and Historia Reiss
 * Fleren refers to the ship between Floch Forster and Eren Jaeger
 * HisuFloch refers to the ship between Historia Reiss and Floch Forster