After reading Chapter 120 of Attack on Titan, “A Fleeting Moment”, it became clearer than ever that the manga is nearing its conclusion.
All the signs are there, with Eren and Zeke now in the path dimension and viewing their father’s memories after meeting the very first Titan Shifter, Ymir Fritz.
What remains to be seen is where exactly this goes and how it will contribute to the ending.
Personally, I think Attack on Titan will end around Chapter 130 so that leaves 10 chapters left.
This impending feeling that the series is in its endgame has caused me to not only come up with a few predictions for Chapter 121 but also come up with an idea of how the manga could end.
And, with that, I would like to go into my predictions for Chapter 121 and the ending itself.

What memories will Eren and Zeke see next and what effect will this have on Zeke?

Chapter 120 ended with Eren telling Zeke it was time to see “the next memory” so, given that this is the cliffhanger of the chapter, I have to believe that this memory is going to be something huge.
But what could it be?
Another one of Grisha’s memories?
Honestly, I am not so sure about that.
Yes, Zeke seeing Grisha’s thought process in giving the Founding and Attack Titans to Eren could contribute to his realization that his father had changed, but I think it would be more powerful for Zeke to see someone else’s memories.
This being Eren Kruger, the Attack Titan before Grisha, who Eren is named after.
We know from the flashes of memories that came when Zeke fulfilled the meme of catching Eren’s decapitated head at the beginning of “A Fleeting Moment” that both brothers now have access to Kruger’s memories.
But what could these memories add to Zeke’s development?
Well, I think this is where Zeke’s father figure, Tom Xaver, comes into play.
In previous prediction posts, I have stated my belief that Kruger and Xaver were working together, based on what Kruger says in Chapter 88.
Zeke learning that the man he thought of as a father was working with someone planning to restore Eldia could be the key to bringing him over to Eren’s side.
Another reason I think we will see Xaver in the memories is because of the mysterious boy seen in the flashes of memories
We know this memory is important because it is the second largest, next to Mikasa from the first chapter, and this has caused many to speculate about who the boy could be.
Some say a young Rod Reiss, or someone from the Warhammer Titan’s memories, but, given what I just said about Xaver and Kruger’s possible connection, I think it is most likely Xaver and that this is pointing to him and Kruger being childhood friends.
There is one thing that does not add up, though, and that is the mysterious hat the boy is wearing, which I can’t remember the name of.
We have never seen any character wear this kind of hat before so it may very well turn our to be someone we have never seen before instead of Xaver.
If it is, though, then I think Zeke will definitely be joining Eren’s side soon.
And, when this happens, the impact will be enormous.

What will happen if Zeke decides to work with Eren?

For starters, we saw in Chapter 120 that Zeke now has control of the Founding Titan power because he arrived in the path dimension without being affected by the first king’s ideology.
This power includes the one to control the Wall Titans, which could flatten the earth if ordered to.
My belief is that Eren currently plans to use these Titans to completely destroy the world so he can protect his friends.
This would explain why he has alienated them, because he does not want them involved in such a horrific plan.
So, if Zeke were to come over to Eren’s way of thinking, then Eren could convince him to initiate the Rumbling, unleashing it on the world.
I think this is probably what will happen in the next chapter or two, when Eren and Zeke stop looking at previous Titan user memories.
As for what will happen after the Rumbling starts, I believe we will get the final, epic battle of the series, with the Scouts and Warriors potentially working together to stop Eren and Zeke from obliterating the world.
Whether or not the brothers will succeed in their attempt at worldwide genocide I am unsure of.
Although, if this is what happens, I certainly hope they are stopped.
Another thing I am interested about is what role Yelena will play in this.
She has been shown to think of Zeke and Eren as gods but is also heavily in favor of the Euthanasia Plan.
So, if she sees Zeke abandoning the plan in favor of world destruction, she will almost certainly not be happy.
And, given that she has more than a few screws loose, this will definitely not be a good thing.
One thing I am anxious about, though, is if Eren and Zeke do activate the rumbling, where does this leave the characters who are not in Shiganshina yet?

Is there any chance of Levi, Hange, Historia and Annie showing up before a series epilogue?

I wish I could say that I can see any of these characters playing a big role in the final battle but, at this stage, I honestly can’t.
Levi is still horribly injured, and probably needs a few days to heal, by which time the fight will be over.
Hange is also with him so this leaves her unable to return as well.
Then there is Annie who is still stuck in that crystal, miles away from Shiganshina.
Finally there is Historia who is pregnant, which does not make her suitable for battle at all.
So, as much as I hate to say it, I doubt that any of these characters will return in a big way, until some kind of epilogue that explains their fates.
If this is the case, then it will be incredibly disappointing because I would like to see every important character play a role in the manga’s ending.
Also it would just be sad to see them left out of the finale, especially characters who have not been relevant in ages like Annie.
However, the series’ writer, Hajime Isayama, is known for surprising us so he may find a way to bring them into the story.
At this stage, though, I doubt it.
But, I will say that I think there is a high chance we could see these characters in flashbacks, primarily Historia.
The reason I think we will see her is because we got an image of her we have never seen before when Zeke caught Eren’s head.
In the image, she is wearing the clothes from when she was talking to the supposed father of her child, with a mysterious figure watching them, and is crying.
I think the mysterious figure was Eren and this is him talking to her about getting pregnant so she can survive.
This means Eren could be the father or it could mean that Historia decided that the father of her child would be her childhood bully (god forbid).
As for when the story behind her pregnancy will be revealed, it could be when Eren and Zeke are in the path dimension but I think this time is reserved for previous Titan user memories so I do not think we will see it for a while.
However, this said, even though I believe Historia will not play a big role in the final battle I think she is pivotal to the conclusion of the story.
The reason I think this is due to a theory about the ending of the story.

Ending Prediction. (WARNING!!! This contains a theory about Attack on Titan‘s ending that I think is highly likely so proceed at your own risk.)

After Chapter 120 came out, one theory began to float around about how Attack on Titan will end that has a lot of evidence behind it.
I heavily buy into this theory and like to call it the Ymir Rebirth Theory.
In “A Fleeting Moment”, Eren finally met Ymir Fritz but, rather than her being this all powerful being, she is actually a slave who has to create and rebuild Titans for all of eternity.
This is shown to impact Eren a lot, with him asking, “you’ve been here all this time, alone?”
Given this, and the fact that Eren values freedom above all else, it seems likely that he will try to free Ymir from her enslavement at some point.
Another part of this theory is that the Attack Titan itself was created to free Ymir.
In any case, If Eren succeeds in doing this then it will change the world of Attack on Titan. 
In order to justify this mindset I will ask you a question: who is the one who creates the Titans?
You guessed it, Ymir Fritz.
She creates them by building them over time in the path dimension, which takes a split second in the outside world.
But, if she is freed from the path dimension then who is there to make these Titans?
That’s right, No one.
Therefore, without Ymir in the Path dimension, Eldians will not be able to turn into Titans anymore.
This will end the threat the Titans pose to the world, that is if Eren has not already destroyed it by that point.
Although, with Ymir now free, the question is what will happen to her?
Will she just fade away?
I don’t think so.
Rather, I think what happens to her is the centerpiece of one of the final panels teased by Isayama a while ago.
In this panel, we see an unknown person holding a baby and telling them they are free.
Many people have speculated this is Eren holding Historia’s child, and if you consider that Ymir Fritz has been reborn as that child it all starts falling into place.
Why would Eren be telling this baby they are free?
Because he has freed them from the Path dimension.
What will Historia name her child?
Who better than to name them after than Freckled Ymir, who saved her life, thus creating this cool time loop where the girl our Ymir is named after is also named after her.
Furthermore, many have speculated that the line “you are free” will be a continuation of the first chapter’s title, “to you in 2,000 years.”
So, in the final chapter of Attack on Titan, Eren will be holding a baby Ymir and, assuming he still has some connection to the paths, will talk to Ymir when she first gets her powers 2000 years in the past, telling her “to you in 2000 years you are free.”
At this stage, considering Eren still has these powers, I also believe he may be dying of Ymir’s curse.
So, in conclusion, here is a summary of my overall theory of how Attack on Titan will end:

Through exploring his father and other Titan Shifters’ memories with Eren, Zeke will come over to his brother’s way of thinking and agree to abandon his Euthanasia Plan in favor of saving the Eldians.
The two will then use the Founding Titan to initiate the Rumbling, sending the Wall Titans to destroy the rest of the world.
Seeing this, the Scouts and Warriors will decide to work together to stop Eren and Zeke, and save the world from this cataclysmic threat.
A lot of characters will die in this big final battle.
Whether Eren succeeds or fails in destroying the world, he will figure out a way to free Ymir Fritz from the Path dimension.
With her now free, Eldians can no longer turn into Titans.
Given this, and the fact that they worked together to try and stop the Rumbling, the Marley government, lead by Magath if he is still alive, will give full rights to all Eldians, ending the cycle of hatred.
A few months later, Historia gives birth to her child and names her Ymir, potentially unaware that her child is the reincarnation of the first Titan Shifter.
Many years later, Eren is dying of Ymir’s Curse and is holding the girl in his arms.
As he does so, he uses the remnants of the Paths to connect with Ymir when she first got her powers and tells her, “to you in 2000 years, you are free.”
And, with that line, Attack on Titan will come to an end.

So that is my big prediction for Attack on Titan‘s ending.
Knowing how unpredictable Isayama is, though, the next chapter will probably crush this theory entirely.
Either way, I am excited to read Chapter 121, and to see how this amazing manga will conclude in the next year or two.