The Fire Glyph shrine is reached by swimming through a tunnel from Razielim Territory.
The main chamber of the Fire Glyph area has several stone slabs with the symbols of Fire Glyph and two vampire murals. In order to obtain the Fire Glyph, Raziel must light up a basket held by a statue of a four-armed demon. Once ignited, the demon statue wakes up and fire blazes throughout the Fire Glyph sanctuary, igniting all fire holders in the area.
The demon statue resembles the demons found in Spirit forges, but is unknown if the similarity is coincidental.
The Fire Glyph area is found in the debug menu under "Dark Eden" section, implying that it was possibly meant to be located near Turel´s Smokestack area. Once it was established that Turel´s area would not be finished in time, it was moved to Raziel´s Stronghold instead.