Hephaestus was the Greek god of subterranean fire and volcanos, and god of the forge. He lived under the earth and used volcanic magma to fire his forge. As god of the forge, he was responsible for crafting all the nice things the gods needed: armour, chariots, palaces, furnishings, ornaments, and the luxury items no royal court can do without. He also created Pandora, the first woman, on Zeus's request as part of a revenge scheme. While Hephaestus was a creative genius, he also had a club foot that made him pitiful to others. He lived alone, underground, with his robotic maidservants made of gold (the original fem-bots). He was married to Aphrodite - a source of creative inspiration for him, but was basically married to his work.
Modern Hephaestuses are often very hard workers, putting in long hours, channelling their intense feelings into hands-on creative work, whether it's making beautiful things that will be admired as well as used, or doing intensive laboratory work. Hephaestuses tend to identify themselves (and be identified) primarily or exclusively with their work. Creating things is how they show others who they are. They start working producing things at a very young age and then just keep going. Hephaestuses tend to be introverted, sensitive, serious, perfectionist, intense, very focussed, easily frustrated and sometimes explosive. They have a genius for technology and "things". They like to work independently, and need to have as much control over their work as possible (genuinely necessary for creative genius), preferring to do something themselves whenever possible rather than delegate. They have a sentimental streak, but in general people are someone else's department. People seem to like seeing geniuses of this sort as handicapped - it appeals to them - but it's the genius itself that's the handicap, because of how difficult it makes it to communicate.
the misunderstood genius; the master craftsman; the technical perfectionist; the mad scientist
the hammer and forge