Wandering Souls and The Importance of Beast Tamers.
This is basically an amalgamation of my half baked thoughts included in Ābhā Infinite's little story so bear with me here.
I think it's important to note that Yuu was meant to be magicless due them, essentially, reality shifting into anyone's worst nightmare (surrounded by boys who are all unhinged.)
Suffice to say it's about playing hard mode.
The reason my Mc has magic is due to reality shifting to a body more compatible to that world. This is based off of @twsty-lav 's AU where Yuu's body is trapped in the coffin but their spirit roams free and they basically attach to a host and shenanigans ensue.
@mia-pon289 already had a theory that Yuu might not be human based off of the fact that both Ortho and Trey had pointed out that Yuu may be pretending to taste things, there's even a point in their theory where they mention that during the VDC (i believe) Yuu tells A-Deuce that its healthy but doesn't comment on the taste.
I don't believe its easy to get isekai'd into Twisted Wonderland without repercussions, which is why I want to circle back to my earlier statement about my Mc (because not everyone's theories line up with mine and they might have a better theory than this) was transferred into a body that was closest to her's.
Twisted Wonderland is like a mirror of our world so it makes sense that there are versions of us that have existed on that plane before or after certain events (hella spoilers for Ābhā right here).
Which is where I bring up my next theory: How important is a Beast Tamer, really?
If NRC already has a (irresponsible) capable Headmaster at the helm what reason would Yuu have to be there?
Some theories (@mia-pon289 specifically) say that it's due to a time loop and that we're on the third but I genuinely believe it's a repetition of an old phenomenon which is where Grim comes in.
We don't know what species Grim is (Chernabogs base and/or Cath Palug is another of @mia-pon289 's theories) or what purpose he serves other than being the Overblot monster at the start of the game.
What of I told you that Grim might be tied to why Beast Tamers exist and why Yuu was called there in the first place (I don't believe it was just Crowley who called for Yuu and more like he and the Mirror of Darkness recited the call for a Beast Tamer because the foresaw Grim's Overblot and possibly the OB boys)
Grim might be part of a species where Beast Tamers need to exist otherwise calamitous events follow (*eyes the four overblotees*) and NRC is just caught in the crossfire.
Which is why I wonder what happened to the previous Headmaster and if a 'Grim' had also appeared but the Beast Tamer failed or was killed off before they could solve the problem. (Its implied that Crowley had been Headmaster for hundreds of years leaving room for my other theories about how there was an abundance of Beast Tamers and 'Beasts')
We don't know much about Grim or what he is, let alone what Beast Tamers exist/existed in the first place.
Why aren't there more Grim's running around? Why aren't there more Beast Tamers? Why did Crowley call for Yuu in the first place and why did he use a chant to get them? Is it a chant specifically for Beast Tamers?