The X-Bow is a frustrating card, capable of shredding your tower from across the arena. Its long range and high damage output demand a quick and effective response to avoid a swift defeat. Earthquake is the best overall counter. Its low cost (3 elixir) and consistent damage allow you to easily reset the X-Bow's lock and deal significant damage. Place it directly on top of the X-Bow to guarantee the hit. Valkyrie works too. Place the Valkyrie directly on the X-Bow to surround and destroy it quickly. Tanky units like Golem also hard counter the X-Bow, use them to distract it and then clean it up with support troops. Utilizing these efficient counters not only stops the X-Bow's assault but also sets you up for a potent counter-push. A well-placed Earthquake or Valkyrie can secure a positive elixir trade and turn the tide of battle.