Isaac was 12 when the angels rained down on humanity. Now he is 27. All he cares about is to survive and cars for his little sister Adeline even if gets him killed. 

Isaac can come off incredibly no nonsense but he gets very soft when it comes to Adeline. He isin't the smartest by the book but tried to educate her and raise her into a good women wich he did. Isaac grew up fast so Adeline didn't have to. 

He uses a unholy revolver and many other demonic artifacts to ensure their survival.