Injustice: Gods Among Us mobile has made an update to the challenges available from now to Feb. 10 2014. Available from now until Feb 10 is the John Stewart Green Lantern Challenge for iPhone, iPad, and iPod Touch while Android players gets the mighty Red Son Deathstroke to obtain for a limited time.
John Stewart Green Lantern [iOS]
The John Stewart Green Lantern challenge is available for a limited time to iOS players and if you play Injustice then you definitely want to beat this challenge and claim your prize for the ultimate Green Lantern skin/card. The card is the only Green Lantern card that has been ranked as a “Gold” card giving him stronger stats and greater health for players to battle with.
Red Son Deathstroke [Android]
Red Son Deathstroke is now available until Feb 10 on the Android operating system and is only available through completing the challenge in the game. You must complete all 5 of the challenge stages to be able to get the Red Son Deathstroke card and once you have beaten it you will be able to purchase Red Son Deathstroke in the shop. It will also be unlocked to infinity.
For either devices, if you do not beat the challenges you will not unlock the card into the shop. As a result once it expires the character will not be available in the shop.