I was responding to the post immediately preceding mine.
But, the, "just say so" approach doesn't really seem like a good fix to me. Its basically allowing anyone who's ever fought an RCV (or can make an obvious logical inference from their description) to take away all the bad guys powers just by saying they do.
And in any case, any of these systems for that side effect are silly because 1) that side effect was flavor text, not in their write up, and 2) all the systems that are being proposed ignore that same flavor text. The text says
"their bellies are a vulnerable point; strike them correctly and hard enough, and all the blood they’ve consumed spills out, often leaving them too weak to fight."
It doesn't say "severely weakened". It doesn't say "Loses all his powers" (which assumes we're playing Vampire the Requiem, where you have to spend blood to use powers. Thats not how feeding works in Dresden. If they exert themselves, they get hungry. It has nothing to do with using that blood to fuel their powers). It says "too weak to fight", if you're too weak to fight you were taken out, or you conceded. There's no way to be too weak to fight and not have lost the fight.