Athena does fight with us, she even takes a human body, making it possible for her enemies' soldiers to kill her, in order to accompany us. She is also willing to sacrifice herself and would gladly let herself be killed if she knew that with her death the war would stop and we would be saved.

I can't say the same of our enemies. They have taken a human body as well but instead of how Athena does, reincarnating in a human body and living as a human. They posses a human body, trapping the soul of the real owner inside that body and submitting it to their will, so even if we kill that body they will survive and only the host will have died.

[The anger is obvious in his words and a few flames appear around him for a second at the memory of Hades possessing his brother. And of his brother willing to be killed in hopes that that would stop Hades. It only last for a moment thought, after all it's in the past and they won.]

Fortunately, Athena's kindness and power have made it possible for us to win those wars without letting those hosts die.