Use Rage with pushes like Balloon, Elixir Golem or Goblin Giant; the boosted troops reach the tower before the defense can react. On defense it can also make your troops attack faster.
Tips
Cast Rage just as your troops are about to reach the tower.
With Balloon, it deals tower damage very quickly.
It only boosts your own troops, never your opponent's.
Strengths
Speeds up pushes and catches defenses off guard.
Cheap.
Weaknesses
Deals no damage by itself.
Costs you elixir if used at the wrong time.
Playing against this spell
Cards that help when your opponent has this spell: