User blog comment:Ab517/New guy with a crazy idea/@comment-26487862-20150611224244

Also, quick note, here are some ideas that I have for characters:

OC: Jack; the spirit of Halloween whose job is to make sure that, well, basically make sure that it's a joyous occasion and now go into chaos. But when an evil entity threatens to destroy that balance, he finds that he has no choice but to ask the Occult Research Club for help. Side note, he once had a thing for Rias years back, and is interested in maybe rekindling the romance they once had, which puts him at odds with Issei.

And as far as the antagonist of this story goes...well, here's a hint: