Ares

Roman Name : Mars

Parents: Zeus and Hera but they did not like him. He was mean and a coward. 

Siblings: Eilithyia, Hebe, Hephaestus and many other siblings from his dads side.  

Relationships: Harmonia his wife. He was the secret but not so secret lover of Aphrodite. This always made her husband mad. 

Children: Eros, Hippolyta, Anteros, Phobos, Deimos, Nike, Himeros, Pothos, Armonia, Alcippe.
God Of: He loved wars and would always start something. He was always making trouble on the battlefield and if not there then in other peoples lives. He liked to always start something in peoples love lives. That is one of the reasons why he enjoyed being with Aphrodite that much more, he knew it made Hephaestus angry.

Symbol: Vulture and the dog because he was a coward and cruel

Greatest Accomplishments: He helped arrest Sisyphos for kidnapping the god of death. Other than that not much more can go in here. 

Worst Accomplishments: Being the type of god that he is there are a lot of things that would fall under this category. One of them being that he slaughtered Adonis for the love of Aphrodite. He transformed his wife into a serpent.