Jeffy/pony fanfic in progress

I'm pretty new to writing fanfiction. I never really liked it much before, but... I think that was because all of the fan stories I had read were really terrible. More recently in my life I've discovered that some fanfiction can actually be really good. I have a creepypasta fan story going on currently, but I've decided I also want to do a creepypasta/MLP crossover fan story featuring Jeff the Killer as a unicorn. I'm thinking of shipping him with Pinkie Pie.

Today I scribbled some story notes in one of my composition notebooks, and I'm feeling that it might turn out to be a pretty good comedic story.

Things I don't yet know about the story:
-specific plot (However, I do have a sketchy hint of a plot.)
-whether or not it will be in chapters or in short story form
-exactly what the genre will turn out to be
-title (not a damn clue)

Things I do know about the story:
-It will be rated PG-13, with some sexual references (I'm not yet sure if I'm going to allow myself to write any sexual activity into the story) and mild violence/morbidity.
-All I've gotten of the plot so far is that Twilight discovers a sick colt (Jeffy) caught in the rain, and she and her friends decide to help take care of him until he gets better.
-Jeffy's back story will be revealed. (It's not the same as the creepypasta.)
-I will introduce my ponysona as a major character in the story, and she will end up adopting Jeffy as her son.
-The Mane Six, Zecora, and the Cutie Mark Crusaders will definitely be in it.

Possibilities:
-I may ship Pinkie and Jeffy. (probably, although I haven't decided how far it will go)
-I may possibly give Rainbow Dash a girlfriend. (still not decided, although it will be known that she does prefer mares)

I'm not sure how many people will actually read this crap, but at least I know I will enjoy writing it. It would be my first ever pony fanfiction. O3O