13. Matt Heafy
If you didn't know it already, Trivium front man Matt Heafy is an extremely talented gentlemen. Not only is he one of the most gifted guitarists in metal, he's also a purple belt in Brazilian jiu-jitsu. Although there are a few good purple belts on this list, none of them are quite as impressive as Heafy.
In the video above, Heafy is recording one of his sparring sessions and shows off some advanced techniques that no novice would be able to even think of, let alone pull off on a guy that is at the level of his opponent. Heafy inverts his guard almost instantly, before the two have an interesting leg lock battle, with Heafy's opponent locking in a calf slicer, while he catches him with a nasty toehold.
You can also watch some of Heafy's jiu-jitsu journey as he regularly streams himself sparring (and playing guitar) on his Twitch channel.