Torrents often vary wildly in quality. You might end up with a "cam" version (filmed in a theater) or a heavily compressed file that ruins the 4K cinematography of Gotham City.
From the search results, select a torrent file that seems reliable and has a good number of seeders. Here's what to look for: batman begins torrent work download best with subtitles
If you are going to do this, here is how to do it right —focusing on the and how to nail the subtitle sync . Torrents often vary wildly in quality