The Antiquian Elemental Guardians are the keepers of the Elemental Cores which sustain the fertility of each continent. They were created by PHOTOS in order to prevent the void of Antiquus. Each of the Guardians possess very powerful elemental powers, but only few of them can surpass the powers of the Ancient Kings.
The Sky Temple naturally contains amalgamite, which is used as a fusion catalyst in melding machinery. Zephyr the Hedgehog is the temple's guardian. He was created by Aero, Deific Wind, in order to protect the temple's Elemental Core: the Zephyrstone. Not only the stone itself, but also the amalgamite in the sacred place. He only allows mining of amalgamite when an Ancient King does so, because he knows that his purposes are for the protection of Antiquus.
The Freeze Cave houses the Cryogenic Crystal, which produces ice that cools the whole continent. Its guardian is Reflecta the Cat. However, she cannot be seen in the cave, because she camouflages in the icy environment. When there are creatures that attempt to steal the crystal due to evl purposes (and there are no other creatures present to stop them), she appears to stop them instead.
The interior of the Nepto Cave can only be traversed by creatures that can survive underwater. Gishil the Fox is the cave's guardian.
The Antarcterrian Cavern houses the Supercooling Icicle, which sustains the Cryolus' temperate landscape. Its guardian is Frigulac the Echidna. He was created by Cryo, Deific Crystal, in order to protect the said icicle.