Injustice 2: 10 Incredibly Powerful DC Characters NetherRealm Left Out
2. Parallax
Given that Green Lantern is in Injustice, it seems like an oversight that his greatest adversary should be ignored, particularly given how powerful Parallax is.
The yellow demon is the literal embodiment of Fear, and while having his traditional insect-like form in the game might be a stretch even by the occasionally ridiculous suggestions of this very list, it would work to have his human-form - Kyle Rayner - included as a Yellow Corps member whose special moves could include unleashing the creature.
In the comics, the character feeds off Fear, which could creatively lead to some stunning staging in-game. Just imagine having to fight a normal fight while the villain projects things that make your character weakened by Fear and him fortified by it (perhaps in the style of the Scarecrow sequences in the Arkham games). Now there's an idea.