He might know how to get in touch with the underground or Cable, who could get in touch with him.
Any other Sentinels are at least 30 minutes away, for reasons that will come up, so he might have time to get away.
It might not be safe to use a prison or guard phone, but there should be a way to use a random person's phone, public internet,dead drops, etc. to send a coded message.
That said, Corona will realize that you are gone, but will have to send a team to find you, as extracting Cable's cell is more important than one person that can survive on their own.
Getting in touch is possible, but only if the team isn't using burner phones (which I'd assume they are), and if there's a town within extremely close proximity (which I doubt there are).
As for the Sentinels, if he isn't extracted by the time they arrive, he's dead. He's too injured to even walk in a straight line, let alone fight off numerous attackers with nothing but gases.
I do want to make note that I'm completely fine with having my characters killed, as long as it's due to reasonable circumstances. I've already got a back-up character made up, so if Cain dies, he dies. It makes sense, realistically, that he would given the circumstances.
<Snipped quote by hagroden>
I must admit that he might not survive if any more sentinels come. They won't just send one, they'll send plenty. If he was part of the team he'd know how to contact them, he will need to figure out how to make it until Corona realizes he's not there. I am very intrigued to read how he deals with the injuries from the explosion.... :) Poor guy. Who is a healer on the team? I mean besides..... :)
And no, I can pretty safely assume that without intervention from the MLA he will die there. While he would know how to contact the team, doing so is not a likelihood as he can't get ahold of them from the prison without risking their lives, and he wouldn't survive a walk all the way from the (presumably) isolated prison to a town of some sort. However, if he is able to escape, the mask is a permanent feature, as well as the deadpool look he'll be sporting from surviving a hydrogen explosion.