"Placing all of his godly power into the weapon had rendered Kratos mortal, vulnerable to the arms of death." - Gaia
Mythology
Mortals (Humans being part of them) are non-magical beings. Humans in particular, were forged from clay by Prometheus. Mortals possess no magical powers and are therefore subject to diseases, viruses, and death. Because of their lack of power, the Gods viewed them as nothing more and everything less than underlings. However, after Prometheus delivered the fires of Olympus to the mortals, Zeus and the rest of the gods began to realize their potential and value; albeit, to a very mild extent.
In the God of War Series
Before becoming a god, and after being stripped of his powers, Kratos was -and once again became- mortal.
