Injustice 3: 10 Characters NetherRealm Must Include
9. The Signal
A very recent addition to the main DC continuity, the Signal (AKA Duke Thomas) is the latest to join Batman's crime-fighting crusade. Duke first appeared in Scott Snyder's Batman run in 2013 as little more than a victim of the Joker, but later went on to form the Robins and then (obviously) become the Signal, after DC's recent Dark Nights Metal event.
Unlike most of the Bat-family, Duke is a metahuman, able to see where light has and will be, allowing him to anticipate his opponents' next move, giving him an edge in most fights. Duke has also been trained by all of the actual Robins (as in Dick Grayson, Tim Drake etc.), along with Batman himself, making him an excellent martial artist as well.
The aforementioned abilities would certainly make for an interesting move set in an Injustice game, and with the character's minimal history it would be easy for NetherRealm's writers to introduce him story-wise.