Injustice Fighter Pack 1 reveals new DLC characters

With a couple of weeks left before the release of Injustice 2, Warner Bros. decides to give us a bit of a tease as to who the new DLC characters are from Fighter Pack 1.
In this new trailer, in an abandoned underground building, three new characters pop out: Starfire (exile from Tamaran, and sometimes Dick Grayson’s main squeeze), Sub-Zero (of course you can’t have a fighting game from Netherrealm Studios without a guest Mortal Kombat character; it does look like his arms are totally made of ice; will Injustice Sub-Zero be a new character card for Mortal Kombat X mobile?), and Red Hood (Batman’s rouge protégé).
Another question to ask? Will Sub-Zero have an active role this time, unlike Scorpion who didn’t have a story role in the original Injustice? It would be nice prep up a side story slightly based on Mortal Kombat vs. DC, before the rebirth of both franchises.
Speaking of which, by the end of the trailer you see a silhouette on the right on what looks like Raiden. Is he going to be the corrupt Elder God version, picked off from Mortal Kombat X?
There are also five more characters in the background, one of them looking like Black Manta on the center-left.
Those answers will be questioned after Injustice 2 launches on May 16^th, 2017 for the Xbox One and PS4.