Matt Mercer has revised his 5th edition Witch Hunter class. You can still find the original here. The class is now called the Blood Hunter (since they are no longer promoting the Vin Diesel movie, The Last Witch Hunter). You can read about it here. I'm allowing the class in one of my 5E games and it seems really cool. I've read the revisions and they seem to be on point. My favorite part of the class is that if you take the Order of the Mutant path you are essentially making a Witcher.