Things You'll Need
Instructions
Advance through the first three quarters of the game, fully exploring the sealed cave in the underworld, losing the eighth and final crystal to your nemesis Golbez, and having the engineer Cid modify your airship so that it has a drill attached.
Hop in your newly outfitted airship and fly to the glowing Tower of Bab-il, then head off to the left until you find a cave entrance. Land the airship and enter the cave.
Cast the "Float" spell on your party from the spell menu screen. This cave is filled with green spots on the ground that will damage your party if you walk directly on them.
Walk through the cave until you find a house filled with fairies. The martial artist named Yang, who was previously thought dead, will be lying in bed. Attempt to talk to him, then leave the cave. You can either exit the same way you came in, or go to the second floor of the house and step on the transporter to be magically warped outside.
Use the drill on the airship to drill your way out of the underworld and back onto the normal overland map. Fly over to Fabul castle and speak with Yang's wife. Your party will receive the "Frying Pan" item from her, which you can use to wake Yang up.
Return to the underworld and go back through the cave--remembering to use Float to avoid the damaging green spots--until you reach Yang. Attempt to talk to Yang, then use the Frying Pan to wake him up. As soon as Yang is done speaking, the fairies will teach your summoner Rydia how to use the "Sylph" summon spell.