Ares is the Greek god of war in its blood, noise and madness rather than its strategy — Athena's opposite number. He is the father of Fear and Terror, loved by Aphrodite, and disliked by nearly everyone else on Olympus, which is itself the point about how war was regarded.
Modern Practice
Ares is worked with for courage, for the clean handling of anger, and for protection in conflict. He is not a god of winning but of what a person is actually like when force is on the table; approach him honestly and expect the same in return.