Any Harry Potter Fanfiction or Quick Transmigration Stories?

Has anyone read I Swing a Greatsword at Hogwarts? The first book was good, but the second one was so hard to follow that I couldn't understand it. I thought the writing was great, though, and the idea was original. The protagonist wasn't overpowered from the start, either. I'd love recommendations with a similar feel, ideally combining fantasy and technology. o(^▽^)o