Once upon a time, there was an evil black goo that was growing in the infinite void, and it needed to be stopped or it would spread negative energy all over the land of the spirits and gods. Hechun created a woman from mirror and glass so the black goo would not see her and would be unable to attack her, and the woman of mirror was created. For what felt like decades to the gods, she fought the black goo and kept it from creeping into the underworld, but this war was eventually a stalemate. She went to get contributions from all the gods, and she was interested in certain contraptions that were being made and used to benefit the goddess of honey and bees. They were black and yellow automatons that were used to collect honey, and take it to their queen. She saw potential, and she purchased the blueprint from her in order to produce these same kind of automatons with modifications. From this, the machines of glass were created.
After setting up a factory and mass-producing machines of glass, they were sent out to fight the endless war against the black goo. They were very successful and nearly wiped it out, but it became smarter and began masquerading itself as ghosts, gods, or people. Soon, they got inside and began sabotaging hell as well as sucking energy away from the gods. They were purged, but the event notified the woman of mirror that no visitor to the underworld could be trusted. She created mirror men to patrol the woods and not allow any visitor in or out of the underworld. It was decided that if someone truly is not a manifestation of black goo, they would be smart enough to sneak past the security. This was a controversial decision but it was effective, as the underworld was kept safe from the growth outside, and it remains in control even to this day.
You can ask the woman of mirror for glass machines to be spirit companions or simply call upon those who have left her service. They will want you to send healing energies towards them for repair, and they are extremely loyal to any who choose to lead them. They may appear as glass flying objects. Sometimes as glass insects and some resemble frisbees or gemstones of various shapes such as pyramids or cylinders. Some take humanoid forms or as birds or other flying animals. Some even choose to appear as glass fish or change their colors.