HP fanfic of an alternative world where Grindelwald wins his duel with Dumbledore

I need to find this fanfic where Grindelwald wins in his duel with Dumbledore.

The story is about a Muggle boy (from Earth isekai’ed) as old as Harry Potter. There is no plot common with the original story, just character names and places.
The MC becomes friends with Neville (Gryffindor) and Hermione (Ravenclaw).

Some changes the author made that I remember:

• There is no one named Harry Potter in this world (I am quite sure the author describes a girl who seems to be the daughter of Snape and Lily but no more mention after)
• Gryffindor is the most despised house due to many dark wizards in history and Ravenclaw is the most popular(?).
• Dumbledore is now sealed in Nurmengard.
• No more Quidditch; instead students need to help teachers during this time (the MC helps the new deputy headmaster once).
• Slughorn still teaches Potions and the MC joins the Slug Club.
• Transfiguration is the class that got cursed.
• A new vampire teacher is teaching that class, Transfiguration. I remember the plot has some connection with this one. He saves a student by drinking his blood out but I don’t remember anything else.