STRO
If you read any other fan-fictions, then you probably noticed that the authors like to keep the story around 90% the same with their mc being involved and alternating the said events however they want to. So, you don't have to think too hard. This is a fan-fic and not an original novel which means you can take the main story and make it play through however you wish. You can also add new elements and arcs to the story when you get inspiration in the name of the butterfly effect. Because some minor and major changes are bound to happen. Anyway,cheers and keep up the good work.