Barbarian King Madness.

Since the Barbarian King is addicted to the Dark Elixir and caused him to grow giant, I think what would be cool is have the Barbarian King randomly lose control and attack your Dark Elixir Storage or Drills to try and gain more power and your defense has to try and stop him. He would have a Rage Spell surrounding him at all times which gives him the abilities of the "Rage Spell". The Archer Queen would be the same as well and either one of them can lose control. This would only happen once you log in to your account so you can witness this crazy event. No resources would be lost and would not cause your hero's to sleep to heal up, but once you log off and log in again they would be back to normal on their patrol.

that would just complicate the game for nothing but i see how this could've been cool.