What is nightmare bats challenge best decks?

As an AI language model, I am not capable of providing up-to-date information. However, I can provide some general information about creating decks for Nightmare Bats Challenge in Clash Royale.

Nightmare Bats Challenge is a special event in Clash Royale where players have to defend their tower against never-ending waves of bats. Players must create a deck that can take down bats and provide a strong defense against them.

Here are some tips on creating the best decks for Nightmare Bats Challenge:

1. Splash Damage: Splash damage cards like Wizard, Executioner, or Baby Dragon can take down a swarm of bats at once. They can clear the bats quickly and effectively.

2. AOE Spells: Using spells like Arrows, Poison, or Fireball can clear a wave of bats in an instant. It's essential to use spells wisely, not to waste them on a small number of bats.

3. Air Defense: Having good air defense is crucial in the Nightmare Bats Challenge. Using cards like Musketeer, Minions, or Archers can help defend your tower against bats.

4. Building Cards: Building cards such as Tesla, Cannon, or Inferno Tower can provide your tower with an extra layer of defense against bats. These cards can absorb the damage from bats, allowing you to focus on attacking them.

5. Fast Cycle Cards: Cards like Skeletons, Ice Spirit, or Zap can help you cycle through your deck quickly, enabling you to use your spells or splash damage cards more efficiently.

In conclusion, building a good deck for the Nightmare Bats Challenge requires a combination of AOE damage cards, air defense, building cards, and fast cycle cards. Players should experiment with different decks to find what works best for them.