At first glance Kratos is just a mercenary who accepts the charge of protecting Colette in her journey of Regeneration. But it's obvious from the start that there is something more to this mysterious man. He is cold and distant but takes special interested in Lloyd and his training.
More character backstory will be given if you are cast in the role.

Here is a reference scene. There are so few scenes that involve Kratos on Youtube and AREN'T major spoiler heavy, that this 24 second scene was all I could find.
https://www.youtube.com/watch?v=w7XDJs1q00g