This is the classic Goblin Giant Sparky deck with a massive boost with the overpowered mirror. Build up big pushes with Mirrored Goblin Giants or Mirrored Sparkies. Drop the rage to increase movement speed and attack speed with your big push to make it unstoppable.
The Mirror is probably the best card in the game right now because you can get over-leveled cards in a game where card levels mean everything. Mirroring your sparkies and goblin giants can make defense very difficult for your opponent.
The Goblin Giant is the main win condition of the deck. Make sure to support him with all the different support units and spells in the deck.
In the early stages, play passively and react to your opponent's plays. If you can defend something with a sparky and counter push with goblin giant, mini Pekka, and rage it can be very lucrative.
In the later stages of the game, you can make huge mirror pushes. Depending on your opponent's deck, try out mirroring your sparkies in the back or mirroring your goblin giants in front of the sparky to break through any defense.