You have to appreciate the fact that Vin Disel is so geeky that not only was his character named Melkor, he was a Witch hunter from the Arcanum book, but now he has a movie more or less based on his character.
https://www.yahoo.com/tv/s/werent-vin-diesels-d-d-230400569.html
http://screenrant.com/last-witch-hunter-elijah-wood-rose-leslie-interview/
Geek and Sundry has also produced a new Witch Hunter class for D&D 5 that you can get here:
http://geekandsundry.com/vin-diesel-brings-matthew-mercers-new-class-to-life-the-witch-hunter-class-for-dd/
So what exactly is a "With Hunter"? Well I have been fairly quiet on the whole concept myself. But before that, let's talk about what has been done first.
I should begin with the Witch Hunter that Vin Disel used and the one that I think of as first anyway, the Witch Hunter from the Arcanum.
All the classes in the Arcanum and the Bard Games "Compleat" books before it were all very thin in nature. Some guidelines, some flavor, but a ton of imagination! The class is described as a dual classed hunter/mystic with "highly trained" combat abilities. They read a lot like Rangers to be honest, save with a focus on hunting down spell casting classes. They get training in two weapons (Weapon Proficiencies) and gain two more over the course of their career. They gain the skills of tracking, reading magic, stealth and spell casting. As spell casters they can't wear armor.
Advancement by level is detailed later in the book (they are on the high end) and they take spells from the Mysticism list, which are similar to Clerics. (Note: I should have covered these Mystics back when I did
mystics for my first Class Struggles).
The witch-hunter gets a maximum of 3 attacks per round when they reach level 13 (remember this is 1st-2nd ed-ish). They also gain a +1 to hit every other level.
There are hunter-like kits for 2nd ed. AD&D, but no witch-hunter really.
3rd Edition and the OGL brought out a number of various witch hunter classes. Many though not till Pathfinder came out.
Super Genius Games had a bunch of books out for OGL/Pathfinder for Witch Hunters.
The Genius Guide to the Witch Hunter and
With a Bullet Point 9 Witch Hunter Feats. With these two there is plenty to run your witch hunter in Pathfinder. Unlike the Arcanum, this one does not use spells but instead has a number of special powers each level. Both methods are fine with me really.
Not to be outdone there is the
Player Paraphernalia #11 The Witch Hunter from The Knotty-Works. This class also gets good combat ability and some powers, but it also gets spells to 4th level. This puts it on par with the Ranger. It has a couple of new feats, but no new spells. Though you are getting a lot here for a buck and half.
So between these three books there are even more choices.
On the OSR/Retro Clone side we have only one product I know of,
PC3 - The OSR Witch Hunter by Jeremy Reaban. This book has a number of nice features in addition to the class. The class does not cast spells, nor does it have a lot of special powers. This is by design and owning to the stated literary source. It does have some skills such as read magic and turn undead. What I think makes this special is the level advancement tables for "First Edition", "Original Edition", "Basic/Expert" and "Cyclopedic Edition". Nice feature if you ask me.
What Should A Witch-Hunter Do?
One question not always addressed is what exactly does a witch hunter do? That's for the player. The question to ask the GMs is what do Witch Hunters hunt when there are no witches (as a class) in the game? The Arcanum version tends to focus on all spell casters. The Pathfinder ones tend to focus on the witch class.
Allow me to toss this one back to you all. Would you or do you use "Witch Hunters"? If so, who do they hunt? What do they do once they have one?