Eren Jaeger has done it.
“From You, 2000 Years Ago” gave us the back story on the founding Titan Ymir. This episode starts off with more details about Grisha fight with the Reiss family. After that we saw glimpses from last week episode when Grisha apologizes to Zeke and then tells him to stop Eren. Which ultimately led them back to the Paths.
In the Paths, Eren admits to Zeke that he received his first glimpsed into the future a few years ago after he kissed Historia’s hand. If Zeke doesn’t bring Eren into Grisha memories then he probably wouldn’t have been able to unlock the founding titans power.
While Ymir heads towards the Tree of Light due to Zeke commands telling the founding Titan to stop the Eldians from ever reproducing again. Eren breaks out of his chains by apparently destroying a part of his hand. It makes sense because Ymir put those chains on Eren and there was no way he was going to break out of those chains.
Eren convinces Ymir by trying to end the founding Titan 2000 years misery of being stuck in the Paths. From there Eren pretty much reveals he’s going wreck havoc the world.
Click here to watch the full episode of Attack on Titan episode 21.