Shan-Yu appears in Kingdom Hearts II as the main antagonist of The Land of Dragons. He originates from Disney's Mulan. His role in the game is very similar to the movie. Instead of being the leader of the Hun army he possesses an army of Heartless. Shan-Yu's eyes and ears in China is his pet falcon, Hayabusa. Hayabusa appears as an ominous warning to others that Shan-Yu and his army are approaching.
 Kingdom Hearts II
Shan-Yu first appears at the beginning of the world with his falcon, Hayabusa. He had burned down a village and was standing in the ruins. He next is seen by Mushu walking into a cave outside the village Sora, Mulan, Donald, and Goofy were in. In order to prove herself to Captain Li Shang she entered the cave followed by the others. However, it was actually a trap. While the heroes are trapped in the cave battling Heartless, Shan-Yu attacks the village, burning it, and turning everyone into Heartless except for Captain Li Shang, Yao, Ling, and Chien Po, who managed to survive. Once the party sees the destruction they charge to the summit of the mountain to encounter the Hun. Although he charged with a mass army of Heartless, Sora and company destroy most of them and Mulan's quick thinking sends Shan-Yu and the rest of the Heartless over the edge of a ridge in an avalanche.
After surviving the avalanche, Shan-Yu attacks the Imperial Palace and distracts Sora with a group of Captain Shang's soldiers, who were actually Heartless. But he is defeated by Sora, Donald, Goofy, and Mulan in a climatic battle. After his defeat, Sora receives the Hidden Dragon Keyblade.
Shan-Yu is a large, muscular Hun with greyish skin, thick, black eyebrows, and a black Fu Manchu mustache. His eyes peculiar colors; the irises are an eerie orange color and his sclera are black. The top of his head is bald, but the hair on the back of his head is quite long and black. He often wears a black hood with grey fur lining and what seem to be two raccoon tails dangling in the front. He wears grey pants and black, knee-high boots with grey soles and a vertical grey stripe up the front. Shan-Yu also wears a coat that is pale yellow on the left side and the front and black on the right side. It has tattered, brown lining and is kept closed by a brown belt. He wears a single black glove on his left hand, presumably for the same reasons falconers use them.
Shan-Yu is a cold-hearted, cruel warrior, ruthless in battle. He cares for himself and his army only. He is aggressive, violent, and rather silent, having no more than five lines in his appearances. He cares greatly about causing chaos and depression. This is shown in Mulan when after an unknown soldier states "Now all of China knows you're here," he gives a cold: "Perfect".
He is feared by almost all of China, and makes a point to ensure that everyone knows it. He is also known for his rather dark sense of humor, demonstrated when he shows mercy to two Chinese soldiers and orders them to get the Emperor to prepare his finest for battle, yet immediately afterwards asks his archer the question, "How many men does it take to deliver a message?", to which the archer responds by taking aim and saying, "One.".
Shan-Yu is the primary antagonist of Mulan, with plans to invade China with his army of Huns. While he has very little screen time until the second half of the movie, he is still the catalyst for almost all the events. During his army, he and his army slay General Li (Li Shang's father) and his men, devastating the nearby village (as shown in Kingdom Hearts II). Like in the game, he attacks Mulan's party on the mountain but is defeated when Mulan causes an avalanche. In retaliation, he wounds Mulan with his sword before being buried underneath the snow, which leads to her exposure as a woman in the film. Surviving the avalanche, he and his remaining men attack the Imperial Palace and take the Emperor hostage, but he is foiled once again by Mulan, Mushu, Shang, Yao, Ling and Chien-Po. Enraged, Shan-Yu corners Mulan on the roof of the palace, where they briefly fight until Mulan traps him long enough for Mushu to launch a firework directly into Shan-Yu's chest, which rockets him straight into the firework tower, where he is apparently killed in the ensuing explosion.
"Hayabusa" is the Japanese word for "Peregrine Falcon."