Question: how to unlock all characters in injustice 2?
Answer: Brainiac. Brainiac, one of the main antagonists of Injustice 2's story, is unlocked by completing the single player campaign with any ending. ... 
Darkseid. As you can probably tell from the above image, Darkseid is a pre-order bonus for the game. ... 
Mr. Freeze. ... 
Vixen. ... 
Grid.