Good morning/afternoon/evening/why the hell are you still awake?
Just to start off, I just finished a Dresden Files Read-a-thon as well as recently finished Dragon Age II, and the idea for a home brew started to percolate in my brain. Long story short, I want to build a class that is a mixture of the Wardens a la Dresden and the Templar a la DAII.
A hero whose only purpose is to hunt down and destroy criminal magic users, or those that have broken one of the laws of Magic. My knowledge of countering a wizard's magic is null save for a giant axe through the chest, but a pissed off battle mage verses an opponent would seem a rather formidable fight.
Counterspelling is an option but I am looking for a combination of spellcraft and martial prowess.
What class would you use? Gestalts are not out of the question.
I am about to run to Mass but when I get back I will post some more thoughts and ideas.
I would take a look at the inquisitor Witch Hunter archetype... I'd say that fits the bill you're looking for almost perfectly. And couple that with the Spellkiller Inquisition. With that you've got yourself a nasty Mage hunter.