Great start to the story mate, I love how Harry found Slytherin's Notebook, I don't think I've seen this idea before and I can't wait to see what you have planned next.
But if you can, I would like it that over time Harry become a real master by controlling his slaves and not make them equles, as there are too many slave stories like that out there and I for one like to see a change it that. It's why I write slave stories where Harry is a true master, and hope to see it here too.
PLEASE update soon