The key elements are few. Ares' character as the god of war gives a certain context to his potential love for Persephone. His bold and often reckless nature might have been drawn to Persephone's grace. But on Persephone's side, there's not much indication of a response. Also, the fact that Persephone was already so tied up in the underworld narrative with Hades made any potential relationship with Ares seem almost non - existent. So overall, it's mainly about Ares' unreciprocated attraction.
In the so - called Ares and Persephone love story, one key element is Ares' inclination towards Persephone. Since he was a god of war, his desires were often strong and impulsive. His attraction to Persephone could be seen as part of his character's propensity for desiring things. For Persephone, she was in a complex situation with her own story of being in the underworld. So her lack of response or any real connection to Ares is also a key element. The whole idea of this relationship is more of a side thought in the grand scheme of Greek mythology, as it lacks the depth and development of other well - known relationships.
Well, there aren't many key elements as it's not a fully - fledged love story. But one could say that Ares' interest in Persephone was a key element, though it was more of a one - sided, unrequited kind of interest. Another aspect could be that Persephone's beauty and her status as a goddess might have attracted Ares. However, compared to her main story with Hades, this relationship was really just a minor footnote in Greek mythology.