fanfiction.net or ao3

I thought it was "the guide development of hair potter-black (so if any of you didn't find if that's why, it's my fault)

The only way Harry can get free of those who wish to use him is to agree to an already made betrothal contract created by Dorea Black-Potter. Will this simple thing change the course of Harry's predestined - at least by Dumbledore - future? Will he remain neutral or will he turn dark after he learns everything Dumbledore's done? Will there be a wedding in future for Rabastan and Harry? Can they have a chance of happiness or will the two Slytherins by nature at least, only presume to use one another?