Each day you have 5 free challenges that you can use in the Arena that you can use to battle other players with more or less the same power as you. As you win battles, your Arena rating will increase and so will the rewards. It’s best to do this on a daily basis, as the rewards you get from battles are very valuable. When each battle round in the round-robin phase comes to an end, all participants will receive what we call "KO Rewards." These rewards are given out based on how many enemy teams y...