Injustice 2 is committed to being bigger and better than its popular predecessor, Injustice: Gods Among Us, and so far that commitment has held true, with updated mechanics, some new gameplay elements, and a roster that dwarfs that of the first game. NetherRealm studios has boasted that the game will offer the one of the largest selections of playable characters in any fighting game ever, and they are proving that claim true with regular character unveils leading up to the game's May 16th release, the newest of which is the New God and dark lord of Apokolips himself, Darkseid.
Darkseid is currently billed as a pre-order exclusive character, but it's not clear if there'll eventually be any other means of unlocking him. What is clear is that he's massively powerful and has one of the most insane super moves - despite some tough competition. According to Darkseid's official character card on injustice.com:
"A being of pure hate incarnate, the lord of Apokolips Darkseid demands the total subjugation of all existence. His merciless obsession has left a wake of suffering and obliteration as he seeks the Anti-Life Equation. With his invincible body, limitless strength, army of Parademons, and the annihilating power of his Omega Beams make him not only a threat to this world, but to every world within reach."
That's obviously a generic description of Darkseid's traditional comic book depiction, as his quest for the Anti-Life Equation doesn't appear to play a big role in the story of Injustice 2. He doesn't even appear to be the villain (or at least not the main villain), as that role has been given to Brainiac, and he looks to be more than powerful enough to keep the heroes' hands full. His status as a pre-order exclusive would suggest that he doesn't really factor into the game at all and is present as more of an easter egg or pre-order bonus for fans, but only time will tell if he has more relevance than that.
Fans of the DCEU might be most excited by the reveal of his look as it could give a taste of the design DC could use for the character when he makes his inevitable live-action big screen debut, although the appearance is mostly a direct adaptation from his traditional comic book look, so there's no major surprises in store on that front.
After Darkseid, the Injustice website shows a total of ten more characters that have yet to be revealed, so fans can look forward to seeing each of those announced over the next few weeks until the game's official launch.
Source: NetherRealm Studios