As expected, Injustice 2 will be enhanced by new characters via DLC packs. The first one, before even the game has been released, has been announced and it features two DC characters and one Mortal Kombat character.
Starfire of the Teen Titans and Red Hood AKA Jason Todd will be joining the fight. These two I think will make a good addition to the fold. But the third.. the third I don't know.
Sub Zero will be coming in to fight the DC heroes and it's something I don't know how to feel. Granted, the Netherrealm fighting games have always had characters from different IPs. I just would rather have this game stick with DC characters.
In any case, that might not be the only Mortal Kombat character coming in. At the end of the video, you can see some shadows of new characters that will be in coming in the future. On the left, you can see the distinct outline of Black Manta, enemy of Aquaman. On the right, you can also see the figure of Raiden with his famous hat.
It's hard to make out the others, but we'll probably get the information on who's coming next in the next few months. The Ultimate Edition will include the first fighter pack plus you'll get 6 more if you pre-order. The 6 are probably the shadows that you see at the end of the video.