Idea: Let the hidden tesla towers absorb a percentage the lightening spell if it was executed within the tower's radius. Then the tower gets to used a portion of the absorbed energy on the enemy troops. Say a level 3 gets to act as a level 4 if lightening was absorbed.
This will at lease give some sort of deterent to those that just pop in and cast a bunch of lightening spells to take dark elixor. It also makes for a better challenge on the placement of the towers and storage.
