When I go through my attack log, it is unusual for there to be an available revenge attack. Here is a “rough” thought.
Implement a mechanism called a “Dark Revenge” attack (it would need to be a new button on the defense log):
A. The Dark Revenge attack would cost the attacker some Dark Elixir, which automatically goes into the loot cart of the attacked player.
B. Dark Revenge can attack through shields whereas a normal revenge, and a normal search cannot.
C. With Dark Revenge attacks, you could also hit a player that just Dark Revenge attacked you, but the Dark Elixir cost escalates with each successive attack. This might make for some epic back and forth battles!
This would also reduce the search time for attacks - if you are willing to spend some dark elixir...

