“ Azure Dragon protects the Son of Heaven. One hundred fight to slaughter the Immortal. „
— Azure Dragon Legion's creed
The memberse of the Azure Dragon Legion were orphans whose parents had been killed or enslaved by the Ancient Ming. They wanted revenge at any cost, so Dark Crow trained them over many years during the Immortal Execution War. Many of them died in battle which is why they are known as the Legion where most die young.
Over many years of fighting and tempering it hardened the soldiers of the Azure Dragon Legion so that they were no longer afraid of death and even if they faced an Immortal Emperor they would still not feel fear.
At the end of the climax of the Immortal Execution War the Azure Dragon Legion was given the task of stopping the Dragon Ming Ancient Dynasty's reinforcements. This was the combined assault of all the Ancient Ming lineages and the Azure Dragon Legion was able to successfully halt their advance creating the opportunity for victory.
Due to their large number of casualties after the war they retired to the Heavenguard Sect.
The Veterans of the Azure Dragon Legion became the Old Ancestors of the Heavenguard Sect and trained the elders and disciples of the sect. when Li Qiye called them to battle against the Soaring Immortal Sect. They also wanted to end the Ancient Ming's remnants that had survived from the Immortal Execution War however they never showed themselves and the Azure Dragon Legion was unable to kill off their old foe. However the Azure Dragon Legion fought against Ren Xian's Empress who had captured Li Qiye.