"Guymelef"'s, or just "Melef"'s are giant mechanical robots, controlled from inside by a pilot. They have the appearance of large suits of medaeval armour, and usually fight using large swords. They are powered via Energists, which are hand sizes spherical crystals found in the heart of earth dragons. The basic defensive/offensive weapon of all the nations in Gaia. Escaflowne is one of them.