Amidst a horrific alien invaded world, a troubled young man's inner demons surface as mysterious entities begin calling out to him in a last chance at human redemption.

Does it work or make you want to read it? I hope so, because I'm writing it. LOL

There's something there. Try making the last part first. Rearranging it.

"A troubled young man's inner demons surface as mysterious entities begin calling out to him from his alien invaded world. Will he listen to them and find redemption or...?"

I don't know what the alternative is if he does not find redemption. You could add that part.