Okay, so I'm pretty sure we now about the teaser tomorrow
Admittedly, I am an amateur when it comes to theories BUT I had an epiphany just now.
In that one teaser back in November (I think), there was a scene where Uzi was holding a crucifix:
This could actually take place after Uzi leaves the spooky door she's about to enter. While N stays behind, she leaves to retrieve the crucifix in order to exorcise the AS out of her. In the previous gif, there seems to be flames or candles:
In order to get the crucifix, she may have to cross some sort of "sea of flames." After doing this, she will be (rightfully) traumatized, which leaves her vulnerable enough for the AS to take over and unwillingly hurt N in the process by crushing his hand.
However, as some people have said before, the triangle on her hand isn't yellow. This could mean that she's perfectly in control of herself. Something must have happened when she got the crucifix...Possibly, she could've met someone who told her information about N.
I know this has been said a thousand times over, but I firmly believe that Nori (if she's even alive) is going to reveal that N is responsible for his disappearance for most of Uzi's childhood.
If that's not it...I'm stumped, literally. There are so many possibilities to the point where it makes it hard to say for certain.
Anyways, I hope you enjoyed my rambling.