Well the thing is with creating your own story's. Is that it needs to make sense. Unless you create a story the continues after the last episode of Bleach. Maybe bring in a new character. An epic character. But the thing with Bleach episodes. You usually find out who's the bad guy later on. I personally wonder how you'll design that.
You know what would be cool? If you come up with an story that has to do with Ichigo's hollow. Make it something like. Ichigo runs into a guy that has a bankai that has the ability to let the other persons bankai choose two paths. Path one could be to stay with Ichigo on his quest to protect those he loves. Or Path two to leave Ichigo. Witch means Ichigo will loose his soul reaping powers. Then make it so Getsuga stays with Ichigo. But the hollow wishes to run free. The guy that ran into Ichigo had no idea about his hollow powers. So once Hollow Ichigo runs loose. Then shit then begins to get interesting.
This is just a quick idea I came up with. But it seems interesting lol. I always liked Hollow Ichigo more than Ichigo him self.