WASDuk.com's Chris Patton reports:
"Although four hours still remain for the Scorpion Challenge Stage to be completed, the next iOS Injustice Challenge Stage has already been revealed by NetherRealm employees on the Facebook group Injustice iOS: Alliance Credits Hub. The group was formed to help players receive more Alliance Credits, which are received when your friends sign up to play Injustice from Facebook. For instance, the Joker in his Killing Joke attire can only be purchased with 60 credits, which means players must have 12 friends accept invites to play, as each accepted invite is worth 5 credits. This sounds much easier than it actually is. Thus, if you are having issues unlocking Alliance Credits, then this group may be for you. Members frequently delete their apps, notify other members, accept friend requests, and then reload the app to accept Injustice requests and give others Alliance Credits."