You had watched over Sam since he was a child, you had tried everything you could to help him in his life, but he was a Winchester, and their life paths had already basically been written, and you couldnt interfere with that. Sam only knew you as a friendly angel that fell from heaven, but there was much more he was going to learn. You didnt know exactly how to tell him, so you might as well just spit it out.
You teleported to the bunker and Sam and Dean were doing research on a ghost case. Sam looked up and saw you, where Dean had never met you before. So of course he whipped out his angel blade and Sam had to stop him from killing you.
You nodded to Dean and turned to Sam, "Can I talk to you in private?" You asked, you were tired and just wanted to get it over with.
"Uh sure." Sam said and you teleported him to a small park. You turned to Sam and fiddled with your hands. "Have you ever heard of gaurdian angels, Sam?" You asked him, hoping he would say yes to spare you explaining to him.
"Yeah, everyone has one, I mean, I think I have one, they just dont do a very good job." Sam said sighing.
You looked down at this and felt bad, but knew you had to tell him. "Sam im your gaurdian angel." You said snd didnt look up at Sam, knowing he would be mad.
"W-What? You are? W-Well whrre have you been all my life! Where were you when that demon fed me demon blood as a baby? Where were you when I was trapped in Lucifers cage?" Sam yelled, obviously angry.
"Sam I would have stopped all those things from happening but I couldnt, it was supposed to happen, your a Winchester, your timeline was written before you were even born. I cant interfere with those kinds of things." Jelly said frowning.
"I also wanted to tell you that I really wont be able to help you at all, today is my last day as an angel." You said looking up at Sams angry face.
"What do you mean?" Sam asked.
"Well like you, I had some of my own problems, and they also had to do with Lucifer. He saved me, and in return I have to become a fully fallen angel, like Cas was for that period of time." You explained.
"What? You made a deal with Lucifer? Are you crazy y/n?" Sam yelled
"No, I would have died if I didnt do it, and I still wanted to be able to be there for you." you said frowning. "I understand your mad-" "Im not mad y/n, im just worried, if your becoming a human then your basically going to have to learn to be a human." Sam said.
"I know that Sam, what I want to know is if it would be ok if I could stay with you." You asked hopefully.
Sam looked up at you and sighed.
"You can, but you have to be careful around Dean, he doesnt like new people very much." Sam said, and you nodded and teleported back to the bunker, wondering what the next day would be like, what it would be like to be a human.