Dark effect

Give a barrack a dark effect with some dark elixir like you boost the barrack with gems.. but the dark ef♥♥♥♥ not make your barrack training troops more faster...
the dark ef♥♥♥♥ make your troops have a dark elixir power, more faster/ stronger with dark suit or dark appearance like an evil mode or something like dark barbarian, dark archer, dark giant and all of them with scary face or bad face..

Well there's already a dark elixir barbarian and archer, the Barbarian King and the Archer Queen, respectfully.

I think it will more interesting if we have like 2 personality of troops.. good and bad side