Dark Void Spell

I'd like to propose a spell that can be dropped on the enemies defensive troops that sucks them away into a black hole. It would eliminate all the troops that are caught in its radius. Seeing as it would be a very powerful spell it could take up 2 spell slots, have a high cost and take a rather lengthy time to create. It would be very beneficial to clanners who are farming and have that feeling of dread when a mass of lvl 6 wizards or Valks comes pouring out of the CC. Drop your Dark Void spell, suck away the opposing forces and return to looting. TH9 required and it would cost dark elixer to create. I'd like to hear what you all think about this idea.