And if you still want a PDF? Buy the ebook from Amazon, Kobo, or Google Play, then use Calibre (free software) to convert it for personal backup. That’s the method even the r/mistborn moderators use.
Tor occasionally gives away The Final Empire for free via their eBook club. Set a Google Alert for "Tor eBook giveaway Mistborn." Reddit usually blows up when this happens—those threads go nuclear hot . mistborn pdf reddit hot
If you're interested in reading the Mistborn series in digital format, there are several options available: And if you still want a PDF