Kamihime is a game where you use what you have. That kind of talk only applies to omegawhales who literally spend thousands of bucks on the game every time a new Hime comes out.
The point is this:If you're lacking in Dragon Eyes, then Ares is one of the last Hime that you're going to Awaken. By the time you have the Dragon Eyes? Maybe Ares can't fit into your Fire team anymore. Maybe she will. Awakened Ares is significantly better than non-Awakened after all, and is thus worth it... IF you don't have anything better.