The Fan of Fen Xing is an enchanted fan that has the power to call upon great winds and banish magical fire. After the villagers of Stormtop Village refused to serve the Iron King, his wife, the Iron Queen used her magic to conjure up a raging inferno on Mount Stormtop that could not be put out thanks to her black magic. To ensure the fire was was kept lit, the Iron King took the fan and locked it away in his arsenal in the Iron Fortress. On their quest to hunt down the wizard Ixis Naugus, Sonic and Tails came across the village seeking water after being exposed to the flames. A resident named Li Moon said she would like to give them water, but it was running low at the moment and was being rationed and that the fire that had been lit a hundred days ago was to blame. Her grandfather, Li Yuen, went on to explain the situation further, and Sonic and Tails decided to go get the Fan of Fen Xing and put out the flames. After confronting a possessed Monkey Khan, Sonic, Tails and Monkey Khan broke into the Iron Fortress and the Iron King's armory, only to be confronted by the Iron King himself. While Sonic and Monkey Khan distracted him, Tails went to look for the fan and quickly found it. He then handed it to Sonic who used its power to blow the Iron king away, literally. They then flew to Mount Stormtop and after some minor interference from the Iron Queen, used the fan to blow the mountain out. (StH: #60)
Roughly two years later in 3237, the Iron King had the Yagyu Clan steal the fan once again for his armory and hide it there, but Espio the Chameleon stole it back and gave it to Monkey Khan to seal the king's defeat once again. (StH: #202, #211)