Little is known about their personalities with the exception of Shan Yu's Elite, but the Huns all share a thirst for power and murderous intent, as well as loyalty to Shan Yu.
Role in the film
The Huns are first seen with Shan Yu in the burning down of a village (though only the aftermath appears on-screen). In their invasion of China, the Hun Army wiped out the entire Imperial Army under General Li in (another) off-screen battle. Almost all the Huns and all their horses had died out in an avalanche while they were pursuing Mulan, Shang, and his elite soldiers, including Yao, Ling, and Chien Po. However, Shan Yu and five of his Elite Hun Soldiers managed to survive, breaking out of the snow and heading to China to capture the Emperor. It is unknown what happened after they failed to capture the latter, though it is likely that if they survived, they were arrested.