Anime world of Attack on Titan is extremely realistic.

Aside from the mystery of the humanoid grotesque looking man-eating creatures called Titans, everything seems to have its secret.

And here are the top 10 mysteries in the anime that still left to be solved.

10. The basement

This is the most well known mystery in the Attack on Titan fandom.

As we now know that the basement expedition will be the next step in the grand scheme of things, hopefully we won’t have to wait too much longer to find out what’s in there.

Since Grisha was at least partially involved in the production of titan serums, a good guess as to what’s down there could be more serums or even a formula the Scouting Legion could emulate.

Or perhaps, maybe a tunnel to an unknown location outside the walls…?  

9. The wall titans

This is One of the most surprising mystery in the anime series.

Right where S2 ended, Mikasa sees a titan inside the wall after Annie made an indent on it.

From Pastor Nick’s knowledge, it seems that the entirety of the walls are completely made up of giant type titans.

Ever since the wall titan made an appearance though, we haven’t heard anything about them other than Rod mentioning they were made by a "special titan" in CH64.

Hopefully we’ll get to find out more about them soon.

8. Mikasa's headaches

Ever since the second chapter, Mikasa has had several stress-triggered headaches with no further explanation on why she has them.

It’s possible that this could be the reason Grisha was visiting her home in the year 844, or it could have a deeper meaning to the plot.

But from all we know at this time these headaches are randomly triggered by stressful events and seem to be recurring.

7. The warriors

We know that Bertholdt, Reiner and Annie came from this “warrior village” in hopes of taking down as many lives as possible and attempt to take the coordinate amongst the chaos.

We know Bertholdt thinks of these people as “children of the devil.” And that Annie seems to have little regard for the people thanks to her father.

But why? Who are the warriors really, and why would they need the coordinate? What is their purpose? Are they really humanity’s enemy or do they simply share a common enemy with humanity and have a larger goal in mind?

6. Ymir Sama

Ymir is probably the character with the most mysteries surrounding her in the anime.

From what we can put together, Ymir was definitely an important person taken in high regard.

In CH40 just prior to transforming, she said she was “just like Historia” where people hated her existence and wanted her dead.

If Ymir was royalty, why would her people want her dead? Well thanks to CH48, we know that she “stole” the titan’s power from the Warrior Village, so it could very well have to do with that.

5. The world is ending

This is probably the most shocking of all the remaining mysteries.

Even without Reiner, Ymir and Uri’s confirmation on this, it was apparent the future was bleak given the expressions Uri & Frieda made immediately upon gaining the coordinate.

There’s no telling if this is an unavoidable event, or just how severe or even what exactly is going to happen, but from what we can gather this seems to be a big problem the characters will have to face near the end of the series.

4. Beast Titan

Not only does he seem unforgivingly brutal when interrogating Mike, he also appears to be the most intelligent titan we’ve seen in the series.

He can talk, apparently speaks numerous languages, and seems to be unaware of what the people inside the wall are doing these days.

But this beast doesn’t seem to be without his own powers. We know he can turn people into titans. So who is this person really?

Even Ymir had no idea who this titan was, but Bertholdt and Reiner seem to have an idea.

3. The asians other minority races

Ever since CH65, we now know that the reason for this is because the Reiss can only control the minds of their own race. When used on any other “bloodlines”, this skill is void.

What makes the Asians particularly interesting is Mikasa’s Tattoo. We haven’t seen the tattoo anywhere on her mother, but assuming she did have it herself leaves us to question the further importance of this symbol.

Since the minority bloodlines from the majority race are immune to the mind altering powers, it’s not far fetched to believe these people held all the secrets to the series, and Mikasa’s tattoo could be the key to unlocking these secrets.

2. Grisha's bolo tie

In the year 844 before Grisha adopted Mikasa, he was explicitly seen adorning a bolo tie. And when we see him again in the year 845, his bolo tie remains to be seen.

From what we know, bolo ties are exclusively worn by high commanding military officers.

So that leaves the question; why was Grisha wearing a bolo tie? He doesn’t seem the soldier type, we know he was a well-known doctor.

It’s possible that Grisha could have been anything in the military from a field medic, to even holding his own private medical research branch in the military.

The later could easily explain how he was able to gain access to titan serums.

1. The mystery girl

This is the most conflicting, confusing and thought-provoking mystery in the entire series.

The title of the very first chapter is “To you, 2000 years from now,” a girl who we think is Mikasa has short hair, Eren’s scarf and is seen smiling as she says “See you later, Eren,” to which then Eren comments on when did Mikasa’s hair get so long, and curiously starts crying for no apparent reason.

So who is this girl? Since we know now that Eren keeps having Frieda’s memories and the fact that Frieda used to have short hair, it’s a common theory now that the mystery girl could be Frieda.

But if she is Frieda and this is where Eren got his scarf from, then why would Eren confuse her with Mikasa?

Since this happens to be the biggest mystery in the series, it’s possible we won’t find out all the answers until the last volume in the series.

(source: tumblr)