I had this idea long ago, I understand that Grogar created monsters in the past, in addition to reviving King Sombra (some believe that he could bring back the Storm King) … remember that Twilight by accident became Fluttershy in Flutterbat, and that at the end of the episode even Fluttershy retained part of his bat side.
 
What would happen if Grogar will awaken the bat side of Fluttershy and recruit her?
 
Honestly, I had the same idea with Nightmare Moon (or the tantabus), Daybreaker and the pony of shadows, although the possibilities are small.
 
What do you think? Would you like to see the return to Flutterbat?