The next challenge is just amazing. You would get to use the electro wizard in your deck and it plays like a grand challenge. You would need to create your own deck with the Electro Wizard. So basically you get to use him and play around what is good to use together with him, about a week before his release.
He would be the best legendary card that would come into the game. He would cost 4 elixir and he enters tha battle with a zap. And he also zaps 2 opponents at once.
At 12 wins, you get a free Electro Wizard. Better stay tuned for that as the challenge comes in 5 days.