Charlaquin
Goblin Queen (She/Her/Hers)
I think I see where the disconnect is. You, and I think @dave2008, are thinking of Dread Counterspell as an ability the DM uses. I, and I think @Flamestrike, are thinking of it as an ability Vecna uses. In your mind, if the conditions are met, the DM can choose to invoke the ability. In my mind, it is Vecna who chooses to invoke the ability, which would require awareness that he has the option to do so.The RAW is knowledge agnostic: it has no bearing on the ability one way or the other. What Vecna knows and how is an after the fact fluff justification. The RAW doesn’t involve that element, but is clear in regards to.im game effect.