WARNING: The following contains spoilers for Season 4, Episode 5 of Attack on Titan, "Declaration of War," now streaming on Crunchyroll, Funimation, Amazon Prime and Hulu.
The final season of Attack on Titan's fifth episode is its most explosive yet. But it's not just Eren's Attack Titan erupting behind a startled Willy Tybur in "Declaration of War" that shocks -- the build-up to this climactic moment is equally as incendiary for onlookers, both in the crowd listening to the foremost Tybur's performance and the viewers at home.
As the nation of Marley prepares to return to Paradis Island and claim the Founding Titan, Willy Tybur, whose family possesses the War Hammer Titan, stages a dramatic retelling of Eldian and Marleyan history at the center of Marley's Eldian internment zone, Liberio. For fans of the anime, it begins as a welcome retreading of Attack on Titan's complex lore. Then, Willy drops some huge bombshells about the world's real history and the real threat that one Paradisian, in particular, presents: Eren Jaeger.
Willy's speech begins by reminding the audience of Eldia's terrible past -- using the unique power of the Titans to install a global empire over a millennia ago, which the rest of the world, including Marley, fought to overturn. But how the Great Titan War, as it came to be known, ended was completely fabricated for the history books. To the knowledge of everyone but the Tybur family and King Karl Fritz (Paradis Island's original monarch), the war was ended a century ago thanks to a great Marleyan hero named Helos. Defeated, King Fritz and a portion of his people fled to the island where he used his tens of millions of colossal Titans to form walls around them. We first saw a glimpse of these Wall Titans in Season 1 during the Assault on Stonehess arc when Eren and Annie clashed in their Titan forms, damaging part of the island's walls to uncover the face of a Titan underneath.
The Eldian King threatened to unleash this giant horde from within the walls should his people ever be threatened again, a catastrophic eventuality called the "Rumbling" that, if enacted, would flatten the entire world. This is the threat that Marley deems Paradis Island to be, providing greater context for Reiner and the others' world-saving efforts.
But, as Willy reveals, King Fritz's threat was a hollow one. In actual fact, he felt ashamed of his people's destructive potential and violent history and never planned on unleashing the Rumbling. Hoping to live out the last of his life in peace surrounded by his subjects, he willingly retreated to the island and used the power of the Founding Titan to erase everyone's memories there, thus creating the gilded cage Eren grew up in. Together with the Tybur family, the king created the legend of Helos to cover up the truth, while vowing to never incite war again -- a declaration instilled, genetically, into the all-powerful Founding Titan.
Knowing that the Founding Titan has recently changed hands, however, is why Willy ends his speech by naming Eren as the single greatest threat to world peace. Without the will of the Fritz family binding it, the Founding Titan is free to command the Wall Titans, and given the hell that Marley has rained down on Paradis Island for so many years, Willy is confident that Eren's vengeance will know no bounds. Considering the tense conversation that Eren has with Reiner right under the Tyburs' noses, he could well be right.
Episode 5 of Attack on Titan is a game-changing one: with the full scope of the world's history laid out and Eren going from its greatest hero to public enemy number one, we're in for the most dramatic and twist-filled season of the anime so far.