Gravity falls return (Bill Cipher X Demigod)

It's a deal

I woke up, and Bill was standing... well more floating there and grinning like a maniac." Nice dreams you got there, kid".he said. I rolled my eyes and was just about to call him a name when Nico (with Will) came to me carrying a drink." here's your drink. Shall I got you anything? Popcorn, sandwich? And who is this?" he said. "Nicolas Damien Di Angelo what did you do?" I said. (A/n that probably isn't his full name Idk. what it is so I made something up) 
"Busted" Will said. "Shut up," Nico said blushing. "Nico..." I said to him in a warning tone. " I might summon some skeletons and now they're terrorizing people at the party." He said." NICO!!!" I shouted." It was an accident I swear!!"." Go. Fix. It. Now!!!"." Fine mom," he said in an annoyed tone. I turned to Bill and said: "I'll make a deal. You'll leave Pines alone, you won't mess with them in any way. No possessions, no further deals. You'll help me protect them and I'll do anything you'll want as Long as it's a Little reasonable. Deal?" Bill smirked and said: It's a DEAL, kid".in his demonic voice and light his hand on fire and offer it to me. I didn't even have any second thought about it. I took it and shake it.
Bill's pov
I used to go to Mia to convince her to make a deal with me, but she refused. Then it actually got nice hanging out with her so when she finally decided on a deal, I didn't waste it. I took her hand and shook it sealing a deal. She didn't look scared instead she looked very annoyed.
Mia's pov
I took his hand. I said: "so what do you want from me? My soul or something?"." Gee kid relax all I want is that you give me a drip of your blood, draw the symbol of my wheel and recite some words." He said. "Ok I can work with that but why?" I thought. "Oh you'll see kid. You'll see."