Pyramids are Magic increasing socket stones used mostly by Magicians and Aloken. From Braiken Castle/Loa Castle and halfway up the Valley of Vengeance, there are +27 Pyramids, however, after that, you will find +36 Pyramids. When you have added max number of Pyramids (depending on weapon size), the weapon will glow blueish (since Pyramids are representing magic, and the mana bar is blue).