1) In “The Fox and the Wolf,” the Nogitsune got shot 4 times and it didn’t even phase him. The Oni couldn’t hurt him, Derek couldn’t, and the taser couldn’t, either. When Void-Stiles sliced himself that let the flies out but that was the extent of the damage. If it was worse he wouldn’t have been able to walk out of there. That was a freaking papercut to him.
Which means that he was “faking it” when Lydia and Aiden found him in that parking lot. Which means that he can manipulate what Lydia hears (we saw it before in “Riddled” - the Nogitsune accidentally drew Lydia to Echo House instead of to the coyote den). Would a body in the middle of a lot all night and day not be noticed by anyone else? He didn’t lie down until Lydia was on her way.
Why would he fake that? Like Void-Stiles said in the loft, he wished that Scott was there. Could Void-Stiles hunt down Scott? No. Could he play dead to get Scott to come to him? Yes.
2) The kanima venom wouldn’t work on the Nogitsune. He was faking the paralysis, too.
The Nogitsune can move a body even if that body is dead (as we saw with his first host in “The Fox and the Wolf.”) He doesn’t need to rely on the body’s heart to beat or the other muscles to move. He doesn’t need food or rest. So it wouldn’t make a difference if Stiles’ body was compromised. That wouldn’t stop him.
Why did he fake that? To cause more chaos. Chaos between Melissa and Scott about the secret. To tell Aiden to go to the school for a showdown with Isaac and Ethan. To see what their plans were. They said right in front of the Nogitsune that they were going to go into his head to find Stiles so he had time to plan his defense.
Here we see someone playing the game Go against themselves. A tie game.
In the next episode we see the Nogitsune and Stiles playing Go. And it’s a tie game. Stiles let the Nogitsune “in.” If we were really seeing his struggle as a game of Go then he would be losing. Massively.
That’s not Stiles. vs. Nogitsune. It’s just the Nogitsune playing himself. Just a trick. He’s in Stiles head and he can hear what Scott and Lydia are saying, so he knew how to make fake-Stiles react to the howl.
4) Who would toss the boardgame into the air? Stiles the chess player, who’s trying for checkmate, who wins by seeing patterns and predicting his enemy’s next move? Or, the unpredictable, chaotic Nogitsune who wants every player on the board to be mixed up and lost and unorganized?
If Stiles found himself sitting on the Nemeton playing a game with a demon, he’d start to count his fingers to see if he was asleep.
5) That chessboard in Stiles’ bedroom -
We’re trying to find clues in it. Derek is trying to figure out why he’s the king and we want to know why Isaac wasn’t even on the board and why the hell Kate and Jackson are. We’re looking answers in the game when it’s the game itself that’s the clue.
They wouldn’t have given that chessboard a second look if those names hadn’t been all over it. Derek wouldn’t still be thinking about it if he hadn’t been labeled the king. That chessboard is Stiles’ calling card. “I was here.” “I am chess.” “If you see me playing chess, being chess-like, then you know that it’s the real me.”
Stiles is chess and the Nogitsune is Go. The Stiles that Scott howled at was playing Go.
6) The most important question: what is the extent of the Nogitsune’s powers? Did Stiles exorcise him or did he exorcise Stiles? Neither.
The Nogitsune can make them see things that aren’t real (the MRI results, hopefully). He can briefly control others he’s not possessing (Oliver in Echo House). We saw hundreds of flies - where did they all go and who all did they go into (where did the flies go that came out of Barrow during his surgery?). He knows exactly where to hurt and manipulate everyone: Melissa’s secret, Scott’s love for Stiles, Derek’s family, Aiden holding Ethan back, Isaac wanting revenge for Boyd and Erica, etc.
They’re just going deeper and deeper into his trap. Every light at the end of the tunnel is just another layer.
And what’s the very best way to distract Scott and the others so that the Nogitsune can run off with Lydia? How about the supposedly real Stiles coming out of the floor. That’s just another trick. That being could be a clone of the Nogitsune. That being could just disappear. That being could die in Scott’s arms right on the carpet then and there, forcing Scott to give up all hope.
Who gave Jared that bomb on the bus? He said “they,” not “he.” What are Chris Argent’s in-laws doing in town? Who was Malia’s mother? Where’s the raven trickster? Why, if Kira’s mom only had 1 more fox tail, are there 5 Oni walking around?
By the way, I hope I’m wrong. I hope every little theory here is wrong. I want bandaged-Stiles to be the real Stiles. I want him to hug his friends and then go behead his evil twin and - voila - happy ending. The real trickster spirit here is Jeff, huh?