Hephaestus was the Greek god of craftsmanship, particularly metal smithing.
Hephaestus was responsible for the armor of Wonder Woman and the Annihilator commissioned by his brother Ares. According to himself, he always includes some sort of weakness in everything he makes, so that no one or thing can get too powerful. He also offered to make alterations to Wonder Woman's armor since it was originally made for her mother, who didn't have Diana's build.
In Greek mythology, Hephaestus was the son of Zeus and Hera, though in many versions he was only Hera's son as she conceived him without help of anyone but herself. He is brother of Ares and the nephew of Hades. Hermes and Athena are Hephaestus' half-siblings.