I’m trying to find a book on AO3 that I accidentally closed the tab on.

It starts out where Harry saves Dudley from the dementors and he has to go to court for underage magic right before 5th year.

Sirius saves Harrison and blood adopts him. Harrison learns about his heritage. Eventually at court Harrison uses what he learns to free Sirius.

The last part I read Sirius calls for the wizard council to fix the ministry after Harry gets detention with the blood quill.

The council changes DADA to a different class with Remus as teacher.

Could you please help me by posting name or link?