Cid Previa Professor Cid Previa is a non - playable character in " Final Fantasy V " . Cid is an elderly inventor and scholar from Karnak who researches the Crystals . Together with his grandson , Mid , who researches at the Library of the Ancients , Cid is one of the foremost inventors in Bartz ' s World . Meeting Cid in the iOS version earns the player the " Scientific Genius " achievement . Story . " Final Fantasy V " . After researching the Crystals , Cid developed machines to produce more energy from them . With the use of the machines , Karnak became one of the most powerful and prosperous kingdoms in the world . Excessive use of Cid ' s machinery , however , was damaging the Crystals ' structural integrity , and when Cid discovered this , he attempted to shut down the machine in Karnak , but was imprisoned . He is freed shortly after the Warriors of Light are imprisoned . The Chancellor of Karnak , having realized that Cid was right , begs him to shut down the amplification device , and Cid agrees on the condition that the Warriors of Light come with him . The Chancellor protests this , claiming that the party was seen leaving the same meteorite that the monsters currently attacking Karnak poured out of , but Cid remains firm , forcing the Chancellor to comply . The four fail to save the Fire Crystal , and Cid goes to the pub in Karnak to sulk . The party travels to the Library of the Ancients and meets Mid , who is outraged to hear Cid ' s state . Mid smacks Cid back to his senses , and using a book he found in the library , the two refit Karnak ' s Fire - Powered Ship to run without the Crystal or the wind , allowing the party to travel the world to save the remaining Crystal . The ship is destroyed in a whirlpool , but the party make it back to the Library of the Ancients . Cid and Mid tell the party they saw King Tycoon in the desert to the west , and provoke a Sandworm attack to allow the group to enter the desert to search for him . While the party explores the city beyond the desert , Cid and Mid fly the black chocobo they left behind to its home where they fall into a pitfall , and meet up with the party who has also fallen into a trap . The group find the Fire - Powered Ship , which escaped harm , and an ancient airship , which Cid activates . When the Ronka Ruins lift off , Cid and Mid instruct the party how to infiltrate the vessel and find the Earth Crystal , and retrofit the airship with Adamantite so it can fly up to the ruins . Afterward , the two tell the party how to open a portal to Galuf ' s World using the crashed meteorites . Cid and Mid make a minor appearance in the Merged World , where they again refit the airship , this time to allow it to transform into a submarine . After the Light Warriors put a stop to Exdeath ' s plans , Cid had all the papers and knowledge he had accumulated about the Crystals destroyed so no one might misuse them while he took the secret to utilizing their power to his grave . The demon Ra Devil was determined to use the Crystals for his own plan and took Cid ' s brain from his grave . Mid tried to protect his grandfather ' s grave but was killed by Ra Devil . In the end , Ra Devil was destroyed and Cid gets his brain back so that he can finally rest in peace . He is referred to as Shido , even in the English version of the OVA , which is unusual , as his predecessor from " Final Fantasy IV " was still called Cid back when it was first localized for the US . Other appearances . " Final Fantasy Trading Card Game " . Cid appears in " Final Fantasy Trading Card Game " with Lightning - elemental cards . Etymology . Cid is a recurring name in the " Final Fantasy " series .