Well, 'OP' in the context of this 'Fury Tries to Kidnap OP Harry Potter Fanfiction' could be the main character that Fury is targeting because of their special powers. Maybe it's a new character created by the author with unique magical abilities that Fury, for some reason, wants to get his hands on. It could be someone with a combination of different magical skills from the original Harry Potter universe, like being able to perform extremely powerful spells without a wand or having the ability to control all types of magical creatures.
One interesting railgun fanfiction could be one where the characters go on a new adventure outside of their usual Academy City setting. For example, they might end up in a parallel world where the rules of their powers are different.
To obtain the railgun in GTA 5 story mode, you might need to reach a specific level or progress through a particular storyline. Sometimes, it could also be hidden in a secret location that you need to discover.
In this volume, the story focuses on the characters' efforts to solve a complex scientific mystery while dealing with powerful adversaries. There are also some unexpected plot twists that keep you on the edge of your seat.