This game follows (rather poorly) the latest ruleset of Dungeons and Dragons (unofficially called its 5th Edition). It is based on a “remix” of the Olympic Pantheon and a mish-mash of Ancient Grecian and Roman geography and history (which a little Nordic and Egyptian flavoring thrown in). As such, things may not make too much sense if you know anything about any of that stuff. I assure you there is a working cosmology somewhere…and that the sprinkling of various historical and mythological figures is done by someone who is an ardent follower of all that stuff.
Except “Edith Hamilton’s Mythology.” That book took all the fun out of “Clash of the Titans.”