Cable goes on the offensive, taking Douglock and Domino to protect a legacy virus scientist who targeted by Bastion. In fighting Bastion’s soldiers, they find a new ally–someone who seems a lot like Predator (from the movies).
Turns out, it’s a new mutant codenamed Abyss. In the end, we learn Abyss is volunteering with the scientist because Abyss has the Legacy Virus.
Abyss is another import from the Apocalypse event–he was in that universe, and now apparently he has a 616 counterpart. There’s no indication that this is the same Abyss. Other Apocalypse characters, like Dark Beast, have an identified relationship to that universe. This guy doesn’t seem to, so that’s why I say it’s not the same one as in Apocalypse.
He also looks a bit different; here’s what he looked like in the AoA’s Amazing X-Men #2.