Before more persons comment something about the sudden relief when Sasha almost died. It was an accident. I forgot to look at their faces when I added the ss.
0:59 I guess Dipper was right about Possession that he wrote on the Journal. "It never left you" He wrote... "...although the entity who possessed you is either gone or dead, the "You" during when you're possessed, manifested inside your head. In a way its kind of like a Split Personality or a manifestation of your other self, your 'Fear', your 'Madness', the person who you are afraid to become" Bill, The Core and Belos may be gone and dead But Bipper, Darcy and Helos are not... They are alive, locked away inside them, waiting.