1. He has magic. has MC's armor been magic tested? I don't think so.
2. As an RPG character, Kratos levels up. MC does not have this benefit. At best he could get better equipment than he had.
3. Kratos is an angel. As such, he can fly
4. Kratos does not age. The dude is old. There's a lot a guy can learn with over 4 millennium.