WARNING: The following contains spoilers for Attack on Titan Season 4, Episode 19, "Two Brothers," now streaming on Funimation, Hulu, and Crunchyroll.
Who would've guessed that Eren getting his head blown off would be one of the lesser surprises in Season 4, Episode 19 of Attack on Titan? After a bloody battle, the Jaeger brothers have finally succeeded in unlocking the power of the Founding Titan. Perhaps unsurprisingly, because nothing is ever as it seems in AoT, everything fans thought they knew about the Founder Ymir, the Founding Titan, and even the Paths (aka the Coordinate) was incorrect, throwing not just the audience for a loop, but Eren as well.
Zeke has sought the power of the Founding Titan to enact his Euthanasia Plan, but it turned out that Eren has reasons of his own, as well. Now that the Jaeger brothers have reached the Paths together and encountered Ymir, the Original Titan, an exposition dump is imminent. Already, the rules have changed dramatically regarding the use of the Founding Titan's powers, so let's go over what we now know about Ymir, The Founding Titan, and the Paths after the events of "Two Brothers."
The Paths Are the Source of Power for All Titans
For much of the early series, Eren Jaeger was said to possess the Coordinate. People like Reiner Braun appeared to know what it meant, but Eren and the audience were left in the dark until now. The place where the Jaeger brothers find themselves is known as "the Coordinate where the Paths converge," indicating that the Paths and Coordinate are, for the sake of simplicity, interchangeable terms for the same location. A vast desert inhabited only by Ymir, the Founder, and original Titan after whom Subjects of Ymir are named.
The Paths are the place to which one with royal blood travels to use the power of the Founding Titan. A seemingly infinite number of years can pass in an instant, as Ymir spends years molding Titan bodies out of sand whenever a Titan Shifter calls on the power of the Nine. It was in the Paths where Ymir healed Zeke's injuries in Season 4, Episode 17. One with royal blood can conjure anything they wish into existence inside the Paths, which Zeke used to his advantage to trap Eren.
Ymir Is a Slave with the Power of a God
Zeke astutely concluded that this mysterious figure who was the path's only inhabitant could only be the Founder Ymir, because who else would be wandering around in a place like this? Ymir's power is beyond comprehension, as she was responsible for the creation and repair of every Titan that's ever existed. It's Ymir's power as the Original Titan that both Eren and Zeke have come to claim, as the Founder allows for omnipotent control over anyone and everyone with Eldian blood.
Unexpectedly, Zeke revealed that despite her godlike power, Ymir is a slave with no will of her own. Ymir exists only to serve those with the royal blood, and she assumes any member of the Fritz bloodline who enters the Paths to be her master. The power that Eren and Zeke have betrayed and killed comrades over is not something they can ever truly possess, it's something that they must order Ymir to carry out on their behalf. Eren is not a fan of slaves, so it will be interesting to see how he interacts with Ymir if he endures whatever Zeke plans to do to him.
The Founding Titan Isn't as Important as We Thought
The most shocking revelation of this episode is that Eren's possession of the Founding Titan has gained him nothing. The Founding Titan has very little power, which would explain how Grisha Jaeger managed to steal it so easily from the Reiss Family. The only thing the Founding Titan can do is transport its wielder into the Paths. As this episode proved, being inside the Paths means nothing if the user doesn't possess royal blood. Long believed to be the most powerful of the Nine, it turns out that the Founding Titan is little more than a key.
While the Founding Titan was being passed down inside the Reiss family on Paradis Island over the years, whoever held it was bound by King Fritz's Vow Renouncing War. However, this Vow appears to be attached to the Founding Titan specifically, not just anyone who possesses royal blood. So now that Zeke has reached the Paths without possessing the Founding Titan, he was not bound by Fritz's will and nullified the Vow. The one rule regarding the Founding Titan that has kept the world safe has now been broken, and at least for the moment, the fate of the entire world rests in the unstable hands of Zeke Jaeger.
