Board Thread:Manga/@comment-27321453-20190908104148/@comment-1327106-20190909235848

I love what is called a stable time loop. It's the only kind of time travel fiction I can tolerate, because there is no going back in time and "changing" the past, because what happened in the past already happened even if it involved some element of time travel from the future. That is the kind that Chapter 121 uses. (If you don't understand, the comic in the link I added illustrates it pretty well.)

The stable time loop is nice because it avoids paradoxes. Any "change" is already incorporated into the timeline and it has always existed this way, and I think this was a smart choice on Isayama's part. It also gives Eren a reason to have drastically changed in the time that he has.

Year 850 Eren got Grisha's memories of Year 854 Eren at the moment he kissed Historia's hand, which happens towards the end of the Return to Shiganshina arc. With Yelena's arrival shortly thereafter in 851, Year 851 Eren would have been able to piece together what he'd seen in the memory he got from Grisha with what was about to happen (allying with Zeke).

Zeke's correct in that Eren's knowledge is limited, and in fact the Attack Titan's power has only helped Eren send things back (Eren has not received any future knowledge except through Grisha, which falls under the usual being able to see the memory of previous inheritors), which neatly restricts his powers, but what I dislike is that we weren't given most of this back in chapter 90 when Eren originally kissed Historia's hand. It feels like a bit of a cheat, since we get part of it, and since we're in Eren's POV when it happens, we should have gotten the rest of it.

Obviously the entire thing happens in a moment in real time, but it could have been cool to have bits and pieces of it placed like fragments without context, so we'd know that something really weird happened there. It's possible Isayama did not have all of this planned out then (since people have been making a lot of comparisons to GoT), but I'm pretty sure he had some of it done, for one particular reason.

We learn that the night Wall Maria fell, Grisha came to the Reiss family and pleaded for Frieda to kill the Titans so his family could be saved. There are two problems with this. 1) Grisha knows that Wall Maria has fallen in a matter of hours of it happening (remember he was away from home on a trip) and 2) Grisha does not know that Carla is already dead. It's still light out when she dies, and Grisha only meets Frieda at night.

If Grisha was anywhere near Wall Maria when it fell, he probably would have run home to his family instead of booking it to the King. But at nightfall he's confronting the Reiss family under the chapel, which is completely on the other side of the capital city from Shiganshina. That's a hell of a trek for Grisha to make if he had firsthand knowledge of the Wall.

But with Chapter 121, what looked like a bit of sloppy plotting/timekeeping actually makes sense. Grisha didn't need to be near the Wall when Shiganshina fell, because Eren gave him the memory. And since Eren didn't (or wasn't able to) show him everything, Grisha's concern about his family rather than his children (since Carla is already dead) makes sense.