The first thing you'll want to do in God of War: Ascension multiplayer is pledge allegiance to a god. Your allegiance determines your stats, to a certain extent, as well as your magic type and starting weapon.
Pledging to Ares nets your multiplayer Spartan fire magic, a big-ass sword, and dominant physical prowess. Devotion to Zeus is awarded with a hammer, superior electric magic and improved defense and "escape" abilities.
Those aren't the only two gods—Poseidon and Hades were visible as well—but they were the only ones available for us to test out.