I remember snippets of the story.
Like Dumbledore telling Fem!Harry (don't know if the name changes) that Voldemort/Tom Riddle (who is no longer snake-faced) offered a ceasefire in return for her signing a marriage/bonding contact and moving in with him. And her begging Dumbledore not to tell Remus and Sirius about it and pretend he's training her for the war.
Then I think she keeps fighting with Riddle and he ends up raping her (she's a virgin) then gives her a gold chain portkey or something which he uses to tie her up.
And there is some old guy called Samson, I think he's Riddle's friend or counselor and they keep sparring a lot. And he starts teaching "Harry" how to control and use her anger in magic.