The Key influence (or maybe I should say Maeda Jun) isn't too apparent in the first episode, but of course knowing Key, I fully expect to bawl my eyes out at some point in this series, as well as the heavy hinting and dosing of magical elements to go along with everything.
That said, episode 1 felt a bit weak to me for an opener. It might be because of my Key bias that I can't help but make comparisons to Maeda Jun's other works. A bit too much comedy and slapstick for my liking, which admittedly nearly overrides the very intriguing Highlander-esque setting and the presumable mystery behind the "battlefield" and whatever it truly is they're fighting against regarding Tenshi and "god".
On the other hand of course those other previous works started out as pretty silly and progressively became very, very, very serious. The silly little things are in fact often the deathly serious ones later on. Deadly serious. Bawwwingly serious. Pretty quickly too, so I really won't hold the first episode against it. Episode 1 did end with a classic semi-magical introspective reflection of sorts I was expecting at some point so it was all balanced, sort of, at the end.
Oh and I'm assuming Key did the OP? Sounds like something they'd make, and the singer sounds like Lia.
Episode 2 was when I realized I should stop comparing it to other Key works because it is both very much Key (the latter half) and very much not Key (the first half?). I actually very much enjoyed it that for all it's silliness at points, it's actually fairly serious if having a rather odd way of presenting it.
On to serious business, there are 3 things that very much intrigue me:
1.
Conformity and Heaven
This series seems to connect a lot to the ideas of religions regarding heaven, purgatory, etc. If anything the battlefield feels closer to an idea of purgatory rather than heaven since it's directly suggested to be the transition stage towards heaven. Theologically speaking the cleansing aspect of the school, where arrivals become students of sorts before they presumably graduate to heaven, is very much symbolic of this but I'm not too sure of the conformity aspect. I've studied theology but I'm not a theologian, however I don't think I've really come across the idea of purgatory being a place where everyone must conform to the norms or risk damnation, at least for Christianity.
For the series, I assume there has to be some very important and solid reason as to why conformity is demanded, and while Yuri seems to consider the rest of the unaware student body to be akin to NPCs, it's really fairly possible for me that like Otonoshi these are simply the people sent there who have not yet become self-aware. Yuri seems to suggest that these people, or most of them at least, have been there for ages and thus concludes to believe that they simply aren't real people, dead or alive (or in between). I personally think that they are the same as them, that there's really no difference in the masses compared to the SSS. To me I'd think that the SSS were the same as these so-called NPCs before self-awareness. It's not outrageous to think that perhaps they only think so because they don't bother to remember the faces of the NPCs and therefore get surprised when a new face that is self-aware arrives. In Otonoshi's case he might have simply been one of the masses and suddenly becomes self-aware right on that spot to be seen by Yuri eventually.
2.
Self-awareness and Memories
One thing I find sort of odd is the lack of self-awareness and memories. Simply put, if this place is meant for one to rid oneself of their physical attachments in preparation for heaven, how can one consciously attempt to make this choice if one cannot remember and cannot think for themselves? If a person on the battlefield possesses no capacity for conscious thought and no memories of his past experiences then how is he supposed to rid himself of these things? Is it to say that the "mindless masses" are those who have achieved this state, or did they become like this by default upon they're arrival?
I'm probably thinking about this too much but this strikes me as odd. If indeed Tenshi's function is to restore this state of zombie-like existence, then I believe that everyone on the school has the capacity to become self-aware at some point by some trigger, that if indeed the NPCs are pre-awares then the zombie-like state is simply a facade to mask/suppress self-awareness, and thus there would have been an original trigger that would have awakened Yuri. In this respect Yuri starts the chain that causes more people to become self-aware.
Yuri in this respect is the original self-aware, as she herself sort of puts it (and thus de facto leader), and she herself is the trigger for everyone else. As such, more supported by the fact that she seems to be the only one with perfect memory of her life upon becoming self-aware, that she is a special existence in this battlefield.
Yuri = Jesus?
Another thing of note is that, given that their weapons explode in their faces if they've never seen it before, it might be safe to say that the internal reality of the battlefield is defined in turn by the (suppressed?) memories of the people there. Assuming the rule applies to everything then would it be safe to say that, since the world seems concrete to some extent, that everyone there has some form of collective memory and/or consciousness that allows the existence of the world in the way they see it? At this point we haven't seen enough of their purgatory so I'll expound on that later.
3.
The Concept of God
Most intriguing and probably most difficult to talk about is the concept of "god" in this world. I guess the only idea we have of the nature of this god is the idea that Yuri has of him. That is to say, she obviously thinks of him as malevolent, unjust and unkind. When you think about it, the very nature of the world's moral code and rules of conformity, zombie minds and violence upon those who rebel against it seems to justify her beliefs. She undoubtedly believes that this god is screwed up compared to the way we think a god would be.
The thing is of course is that she likely tackles the problem most people in a religion have, whether they like to admit it: the silence of god. She questions god as to why horrible things happened to her, and probably why such things seem to continue in this world in-between, but I guess the god of this world doesn't answer. Only silence, so she is forced to make her own image of him based on her experiences.
One could say that Tenshi is likely to be the (rampaging) hand of god in this world, but I have this suspicion that she's not, at least not wholly so. I don't know why I believe this but I don't think Tenshi exactly acts out the will of god so to speak, that there's probably something more to it, something I'm sure will be revealed eventually.
And that as they say is that. My fingers and my brain hurts. Damn you Maeda Jun and your metaphysics.