Reactive Counterspell
From Compendium of Worldly Lore
Needs review
Source: Magic of Faerun
Description: You can react quickly to counter spells cast by opponents.
Prerequisites: Improved Initiative, Improved Counterspell
Once per round, you can counterspell an opponent's spell even if you have not readied an action to do so. This counterspell action takes the place of your next turn. You can't use this feat when you are flat-footed.