[Rataxes]

Well personally, I think the by far biggest problem with mages for fighters is Mantle-like spells, especially when you're dealing with Liches. Stoneskin can always be pierced with elemental dmg weapons, but unless you got a crappy unenchanted weapon lying around (and not even that will work against Liches) - which means the enemy will still have several rounds of uninterrupted spell casting due to stoneskins and contingencies - you're utterly out of options as a pure fighter when the mage keeps casting Prot from Magic Weapons. Not even Inquisitors can deal with them painlessly since high-level mages like to cast Immunity to abjuration.

The thing is that mages are minced meat vs any fighter whose hits actually connect, so the Wizard Slayer wouldn't really have an edge here.

But, if the 10% Spell disruption thing stands out as the one Affect-on-hit that pierces every single god damned protection a mage can think of, then I'd gladly consider him the best anti-mage fighter in the game.