Every time you read about someone getting a 'Gamer System' it generally places them at the right fucking time period for your knowledge about whatever universe you have chosen.
Onyx gained the Gamer System but now she has to figure out how to stay alive for, or travel 1000 years to the future so that she can actually use the knowledge she knows about the HP Universe.
The beginning is hard to read without wincing several times. Though I understand the author was going for effect. There should be a trigger warning in the synopsis for trauma survivors. Some awkward sentences. But fairly easy to read.