I miss Annie to bad she's in that crystal. I think Annie had a thing for Eren cuz she was crying when they took Eren from her in her titan form. A lot of subtle subplots in this manga.
Well, the last chapter for example, might suggest that the reason why Titans ate humans, is that they themselves want to regain their humanity(subconsciously), but since they don't know which people hold the Titan Power, they eat all. By eating one of their friends, Ymir have gained(stolen) the Titan Power and was able to regain her humanity.
This might mean that there are Humans, Titans that were once Humans, Humans with Titan Powers and actual Titans (like the monkey ? The way he was talking seemed as he never considered himself a Human, although he certainly can turn into something else, since no one noticed a big-ass ape behind the walls).
I get this theory that that giant ape was responsible for turning a village into Titans. No walls where breached. I doubt he carried them over the wall.
Since those powers are used subconsciously and instinctively, instead of creating a foreign object, it mimics the human body itself, to which the mind is already accustomed to. Instead of learning how to use it from zero, it simply uses mechanics that it inherently knows about. Basically, the mind power is shaped after bones, joints, nerves, muscles, because those are the things that human brain is used to controlling and moving around.
You could say that people are actually encompassed in their own mind powers, moving around using their telekinetic powers shaped after the human body, while being in a state between coma and hibernation (Ymir described it as an never ending nightmare, from which she finally woke up after many decades thanks to absorbing the Titan Power from one of their friends). This would explain why the actual Titan bodies weight almost nothing, while possessing the power the power and durability to destroy armored walls easily. It could also explain why the human brains perceive their forms as simply giant humans, since that's how the power is shaped like, plus it is much easier for the brain to understand what's going on by projecting it that way.
Since those powers are remained hidden within the brains of every human being, it can run amok anytime, as long as a certain impulse where to activate them, like direct contact, or signal from the ape giant, or in case of Titan Powers user, self-injury (of course the self-injury is like turning on a computer, you still need to input a command for something to happen on it, like picking up a spoon).
It's possible that the Colossal Titans in the walls are actually blocking (or absorbing) some kind of signal that turns people into Titans. This would explain why the sect wants people to remain within the walls and don't like when people go beyond them.
I have seen a few of those and I must admit, this one seems to be the best :P:
attack on titan before the fall 1
The first chapter in a back story of attack on titan. 70 years before the current timeline.
So this is before inventing the 3D-movement gear. Does this mean that this is also before the first expedition ?
A lot of Manga had prequels lately.
I heard that this is based on the novel prequel.