You can officially download the full PC version through several major digital storefronts:
: Often provides Steam keys at competitive prices. Injustice 2 Download PC Game
: The most common platform for the full game. You can find both the Standard and Legendary Edition (which includes all DLC characters like Hellboy and the Teenage Mutant Ninja Turtles) on the Injustice 2 Steam Page . You can officially download the full PC version