I honestly don't blame you for thinking it's hacked; the fact that it's shiny is pretty suspicious, and Blast Burn and Hydro Cannon are downright shifty on it. And yet... It's totally legit. It was a Japanese, Taiwanese, and Korean exclusive event (so it should be in one of those languages) to promote the 18th Pokemon movie, and it had exactly the moveset you were talking about. It could even come shiny! From my experience, it's also pretty rare, so I'd definitely hang on to it. If you want to double check to make sure that it's 100% legit, though, then check out this page right here.