I suspect that there may be something like this in Spellbound, but I am doing a conversion of the War of the Burning Sky saga and was planning on starting it this weekend, and it uses counterspell rules extensively.
He's my first draft. It needs work... I want the ability to counter reflexively to be available as early as possible, but so far this chain suggests that come last in the chain. Also, I definitely need a better benefit for supremacy that doesn't totally throw the game out of whack.
Prerequisite: Ability to cast 1st level spells.
Benefit: You gain a trick:
Flexible Counter (Spellcasting Trick): The spell's normal effects and range are ignored. Instead, your spell may be used to counter any spell with a level plus casting level equal to or less than the level of your spell plus casting level - 1. You may use this trick once per round, up to a number of times per scene equal to your number of spellcasting feats.
Prerequisite: Counterspell Basics
Benefit: You gain a stance:
Spellguard (Stance): You can use a counter spell effect (using a Counter Spell spell or the Flexible Counter trick) as a readied action to counter a spell targeting you as it is being cast. Doing so requires you win an opposed specllasting check against the spell's casting roll (for arcane magic) or against a resolve check by the caster (for divine magic.) You may not take the run action.
Prerequisite: Counterspell Mastery
Benefit: You can counter spell (using Counter Spell I or the Flexible Counter trick) effects out to close range, and you gain a trick:
Spellduel (Total Defense Trick): You bonus for total defense is added to the DC of any spell targeting you or which includes you in its area.