Valves

Valves are a recurring theme in the Silent Hill portion of Angels & Asses, as they hold great importance to the cycle of the normal world, the Fog World and the Otherworld.

Symbolism & Usage
Like their functions in the normal world, valves regulate the shifts between the dimensions. They must be watched over at all times to ensure the proper order and maintain the cycle of death and rebirth going. Valtiel is the sole keeper of the Valves while Xuchilbara and Lobsel Vith protect it as part of their duties. Valves are a recurring theme in the Fog World, as are Industrial Fans and the decay but remain immobile to other characters. It is said that only high-ranking individuals such as Michael and Lucifer could change the direction of the valves but due to the power-nullifing effects of the Fog World, there may not have been an attempt to test the theory.

Xuchilbara's Riddle
During a particularly feisty moment, Xuchilbara let slip a riddle to Kimball Cho directed towards the Fog Patrol:

''One of them made the other forget, One was the Holy Mother until she aborted God, One was supposed to be a sacrifice for God, and the last one got the Gift from his father.''

The riddle itself is quite difficult to solve but it holds the names of those who can "spin the valves at will". These five people have the ability to control the shifts between worlds as they were touched by the Silent. Three of those people have been identified as: The other two remain anonymous but House claimed that if the person who forgot unlocked the memories, that person would go insane and the shifts will become unstable. Only House and Shepherd have some varying control over the shift but nothing like those by the Yellow and Red Gods.
 * Heather Mason/Morris
 * Greg House
 * Alex Shepherd