Bevendre

Very true.  Let me rephrase, there’s no reason for Twilight to become Sparcrow in Raricow from drinking the same concoction that’s made Rarity into a cowpony.  It wouldn’t make sense for the same potion to have completely different effects on two subjects within a short time span. 

If someone wants to make Twilight Sparcrow a thing, then by all means do so!  It’s an interesting idea and I’d love to see the setup and payoff.  It’s just not an idea that fits in with what would happen given the events in the blog.