Yet, Armin assured Eren he would take the role as savior of the surviving humanity to tell his and his comrades story to Humanity across the sea and Humanity in Paradis, and let it be known how mortal enemies eventually found common ground to work together towards survival.

As we noted and Historia knew well, conflict had never ended, but Eren slowed it down in order to level the field so that Paradis and the rest of the world would grow again from tragedy to a fair level.

One hell ended and there are no more titans, but the other hell always remained since the dawn of history, the hell of men killing each other.

Nonetheless, Armin and the Scout regiment made choice to step into that hell and to look forward to tell the entire world their story as Paradis and the Outside would be going once again into a deadly arms race.

This story started with birds soaring into the sky, and it poetically ended with a bird consoling a grieving Mikasa reminded of fond memories of the distant past when she and Eren enjoyed taking naps at the side of the leafy tree.
She dragged the regret, but poetically Eren inspired her from beyond the grave for her to move forward once again.

Seasons come and go, time flows and passes by, friends come to visit and pay respects to the grave of their departed friend, but time and nature remain unfixed and relentless.

At a blink of an eye, Mikasa has found a man and became a mother.

More time passed by, and she became an ailing grandmother mustering her last breath to visit his beloved Eren's grave.

Time is relentless, and Mikasa passes away, and the audience were left what would become of Paradis.

Time continues to move forward, and civilization in Paradis keeps fluorishing like a river bed unstoppable.

Time blinks in an eye, and Paradis has become in a distant future into an advance civilization, however....

Human nature never forgets and is relentless, as Paradis is laid to a scorching inferno and turned into rubble by the forces of the rest of the world. Eren's prediction was inevitable, because the cycle of hatred and violence never stopped. A saving grace was likely that Erens' friends, at least, lived long, fulfilling lives, and passed away years or decades before the apocalypse came raining down on Paradis so that they neither witnessed nor lived through that retribution.

Indeed, the living were jealous of the dead.

On forward to the distant future, that in spite of human's cycle of violence and hatred, nature moved forward and reclaimed the remnants of Paradis civilization.

In that distant future, a lone boy and his trusting dog wander off searching whatever they can scavenge at sight. Little do they know that the next moment they spot the humonguous, towering figure of the tree that once housed Erens' remains.

The boy stopped pondering his options, but, as Grisha Jäger once said, human imagination and curiosity cannot be stopped. So the boy following his gut chose to keep moving forward into the tree, as if he was being beckoned by forces beyond his comprehension, or, perhaps, he was being extended an invitation...