Side Effects Of Insanity

Not according to plan

"Body...shutting...down..." (I don't remember this part exactly, so here you go) Bill began to slip from the shell he was currently in. No no no! The human body was frustratingly complicated to him. Dipper, still a ghost, say Bill get flung out of his body Nows my chance! Without thinking, he shot forward.
        Bill, on the other hand, rerouted his flight path back toward Dipper's body. The deal wasn't off, so the body was still his. Seeing Dipper flying towards it, Bill knew he had to get there first. Dipper saw Bill getting bigger out of the corner of his eye. Both sped up, and smashed into the body at the same time. Dipper's soul (Feeling Undertale vibes...) and Bill essence fused together painfully. Both felt nothing, yet felt everything.
        Dipper slowly regained consciousness, and the white noise cleared. "Ugh, what happened?" Before he could move, Mabel smashed him with a hug. "Bro, you're ok!" Confused the audience began to applaud, Gabe was giving a standing ovation. They all thought it was part of the show, for the reverend to crash the wedding, and began leaving for the after party (that was there right?). Some the auditorium was almost empty, not including Dipper and Mabel, Stan got up and began walking towards the door. "You two come out when your ready." Mabel turned to Dipper. "I'm just glad Bills gone. Bro bro, I'm going to go hang out with Gabe. I'll be back around 11." Something was off to Dipper, but he couldn't place his finger on it. "Y-yeah, ok."
Without another word, Dipper walked back stage. "What's wrong with me? I feel different, and I didn't see what happened to Bill." The door to the dressing room had been left open, so he walked in and changed into his normal attire. He began walking out the door, when he caught a glimpse of himself in the mirror. Hair was sticking out at every angle and he had dark circles under his eyes. "What did Bill do?" A little voice in his head answered. Oh, nothing much. I'm pretty sure you saw most of it, so I wouldn't worry Pine Tree. "W-what? Where are you Bill, I know that's you." Again his thought answered him, My my, you sure catch on fast. I'm in your head obviously. "How did you get there? I thought you left after I got my body back!" Bill laughed, Well, sorry to disappoint you. Turns out we both flew back in at the same time, and bound my essence and your soul. Now we're together for all of eternity, even after you die and go to the next life. We now share everything, memories, thoughts, and a body. Think of it like roommates, except in your head. "No no no no no, I can't be bound not you! That would be torture!" Without warning, Dipper's eyes turned yellow with a black slit down the middle. "Yeesh kid, take it down a notch. I'm not going to do anything that horrible. I'll let you lead for a bit, because somethings coming up, and I want to prepare on my own terms." Dipper was scared, to say the least. I Bill could possess him anytime, he could do a lot of things, none of them good. "Kid, like I said, I'm not going to do anything that bad. And certainly not kill anyone, if you were wondering. " Only one thought passed through Dipper's head. What am I going to tell Mabel?