After the defeat of the Dark Masters and Apocalymon, Gennai asked the DigiDestined to forswear the power of their Crests to awaken the Sovereign; only Azulongmon made contact with Gennai, and worked with him to prepare for the unfolding schemes of Myotismon, Daemon, and Dragomon.
Each Sovereign corresponds to both a figure of Eastern mythology, and the ancient Digital World symbols embodied by the Crests and Digimentals.
Azulongmon is Seiryu the Dragon and the Guardian of the East. He is connected to the powers of Hope and Light. He is the wisest of the Sovereign, and also one of the Four Great Dragons.
Zhuqiaomon is Suzaku the Phoenix and Guardian of the South. Zhuaqiaomon is believed to be connected to the powers of Love and Courage.
Baihumon is Byako the Tiger and Guardian of the West. Baihumon is believed to be connected to the powers of Friendship and Knowledge
Ebonwumon is Genbu the Turtle and Guardian of the North. Ebonwumon is believed to be connected to the powers of Reliability and Sincerity.
Vague rumors have spoken of a fifth Sovereign, more powerful than the other four. If true, Huanglongmon would be Guardian of the Center. It is unknown if he would be associated with any of the ancient crests.
The Sovereign had as their servants the Devas, twelve powerful Ultimates based on the twelve signs of the Chinese Zodiac. When the D-Reaper reawakened, one of the Sovereign, Zhuquiaomon, became enraged at the human world and sent the Devas to attack it one by one: they were defeated by the tamers led by Takato Matsuki--save for Antylamon, who became the partner of Susie Wong.
Azulongmon was in frequent contact with Goro "Shibumi" Mizuno, one of the members of the Phosiovita Project (aka "The Monster Makers")