Attack On Titan Introduces a New Rebel Faction in Season 4

Attack on Titan season 4 has introduced a new rebel faction to its chess game of warring nations: the Anti-Marleyan Volunteers. (SPOILERS) This group of rebels formed inside the ranks of Marley's military empire, as various soldiers from the nations Marley conquered with its Titan might, all bonded together in hopes of rebellion. However, the flaming embers of hope all but burned out for the group over the years of being forced to serve in Marleyan military ranks - until they found a true symbol and leader in Zeke Jaeger. Now the Anti-Marleyan Volunteers have made the voyage to Paradis Island, to ally themselves with Eren Jaeger and the Survey Corps.

In Attack On Titan anime episode 68, "Brave Volunteers", we finally get the portion of the story from the POV of the Anti-Marleyan Volunteers. That story involves finally answering the question of who the mysterious Marleyan soldier was that lured Cart and Jaw Titan users Pieck and Galliard into a trap, during Eren surprise attack on Marley's leaders. That person turns out to be Yelena, the de-facto leader of the Anti-Marleyan Volunteers.

In a flashback, we learn about the infamous Marley naval scouting party and never returned. It turns out that the Survey Corps didn't kill the scouting party: Yelena and the Anti-Marleyan Volunteers used the opportunity to finally defect from Marley, and join forces with Paradis Island.

When the Survey Corps makes contact with sympathetic warriors from not only Marley but around the world... it changes everything. The Survey Corps gains access to knowledge and technology beyond anything they'd ever dreamed of outside their Medieval world inside the walls. They also gain all the intel they need about who their enemy across the sea truly is.

However, the Anti-Marleyan Volunteers bring one secret that totally rocks the Survey Corps and the entire leadership of Paradis Island: their leader is Zeke Jaeger. The Yelena delivers a message from Zeke revealing that his true intent is to use the power of the titans to free the Eldian people from Marley, and build a new Eldian empire on Paradis Island.

Zeke's plan is to cause the Rumbling, an cataclysmic event that would see the walls of Paradis unleash an army of Colossal Titans to stamp out all opposition on the planet. That Plan is all the confirmation that Eren needs to hear that Zeke truly wants to help, and now the Survey Corps and Anti-Marleyan Voluteers are united in some clear (and violent) shared purpose.

Attack On Titan season 4 is streaming new episodes Sunday on Funimation and Hulu.