Normally I'd defend MatPat, but after watching that video, I find that very hard to do. Honestly it's hard to watch that opening he did for it, and not think he is doing an April Fools joke or something. He never once mentioned the gas-station attendant, which as we all know (by now since it's 10 years later as he kept saying again and again) was Izanami, who gave Yu, Adachi, and Namatame their powers. Also, while he did mention. Those three, he tried to say that Adachi had a shadow in the form of Amino-sagiri...which would a simple mistake, had Adachi not just got his butt kicked while using his own persona, Magatsu-Izanagi. Which as Mat claimed to understand, wouldn't be possible. Honestly, he could've made a better theory video had he talked about how Mitsuo Kubo didn't get a Persona...that might have been interesting to think about...but to think that Teddie is Yu's Shadow is grasping at some very thin straws.