Hephaestus was the Greek god of blacksmith and volcanoes. He was lame because his mother, Hera, throw him from Mount Olympus cause he was not as beautiful as she expected. In compensation, Zeus married him with Aphrodite, the most beautiful goddess (but obviously she was forced and unfaithful).
Hephaestus' room in St. Francis' Folly features a sphere which can shoot lightning and a large hammer which falls and causes a block to fall allowing access to the Hephaestus' key above.
In Tomb Raider, however, there was a confusion and the god was called Thor. But Thor was a Norse god so he had nothing to do in the Greek level. In Tomb Raider: Anniversary, it was corrected and the god is renamed Hephaestus.