Voldemort and Horcruxes
I'm writing a fiction where I need a defeat of Voldmort, but not quite as large of a battle in the seventh book. Not to mention, that my fiction takes place in the fifth year. So, that said, I need a way of defeating Voldmort for the mean time. Like, I was thinking about creating my own horcrux for Voldemort, in which gets destroyed and he becomes weakened. In my story, there's a romance between Harry and an other character which happens to be Snape's daughter that had been in hiding for some time. I was think Voldemort might think that if he killed her, Harry would be left too weak to manage against him. The only way to weaken someone like this, is if the love is a very true love, a love that was destined. So, my idea was that Voldemort attack Hogwarts in order to capture and torture the gilr in front of Harry, eventually murdering her. But, with a quick plan from Snape that Harry was never aware of, Evangeline (the girl) gets sent off under Voldemort's nose, and replaced by an unconcsious rat, force fed enough Polyjuice in order to make a duplicate of her. She is murdered unconsciously. (Not her, but you know.)
So, what would be a good way to get Voldemort defeated? It's not supposed to be epic, but the last couple chapters, since the story in more revolved around the romance. Should I make him a horcrux? And how weak would he be if it were destroyed?