Weyoun

Weyoun was a high-ranking Vorta in the Dominion. He has been cloned at least nine times, as of 2376.

Weyoun 2
The second version of Weyoun once had a romantic relationship with one of Kilana's clones. 

Weyoun 4
This version of Weyoun lead a team of Jem'Hadar, including Omet'iklan, Toman'torax and Virak'kara, to locate a group of rogue Jem'Hadar who had taken over an Iconian Gateway. Weyoun and the Jem'Hadar were rescued by the USS Defiant after they were attacked. The two crews later worked together and were successful in destroying the gateway, although Weyoun was killed by First Omet'iklan for doubting them. 

Weyoun 5
The fifth version of Weyoun was assigned to be Gul Skrain Dukat's Vorta advisor after the Cardassian Union joined the Dominion in 2373.

Weyoun first met Dukat in the Kamiat Nebula, the first meeting Dukat had with the Dominion. They discussed the proposed rebuilding of the Cardassian fleet with Dominion assistance, as well as the future of the former Maquis colonies. 

Several months later, Weyoun came with Dukat to Deep Space 9 to persuade Tekeny Ghemor to return home to Cardassia. After Dukat's plan to kill Ghemor with voraxna poison in kanar, Weyoun drank it. His Vorta physiology combated the poison, although he noted it was "quite toxic". 

Weyoun returned to DS9 several weeks later to open negotiations for Bajor to sign a nonaggression pact with the Dominion. He later detected Elias Geiger's cellular regeneration and entertainment chamber and brought the scientist and his possessions aboard his ship. Jake Sisko and Nog were also brought aboard and Weyoun gave them the Willie Mays baseball card they had been seeking. 

Weyoun made another journey to DS9 several months later, this time to warn Sisko and the Federation to not try and stop the Dominion by constructing a minefield around the Bajoran wormhole. This "diplomacy" failed and Weyoun later participated in the attack on the station. 

During the Dominion's time in control of Terok Nor, Weyoun persuaded Odo to sit on the Ruling Council with himself and Dukat, in return for allowing the Bajoran Militia more influence in security matters. 

The fifth Weyoun was killed in a transporter accident in early 2375. It is believed that Legate Damar may have had something to do with the accident. 

Weyoun 6
Shortly after the death of Weyoun 5, the sixth incarnation of Weyoun was activated. It soon became apparent that this newest version of Weyoun was not like the previous incarnations - believing that the Dominion War was a terrible mistake. Using the name of one of Odo's contacts, he got a message to Odo, who would later travel to meet him. When the two began to travel back to the Federation, it was revealed that a new clone, Weyoun 7, had been activated. Weyoun 6 killed himself to keep the Jem'Hadar from destroying the runabout that he and Odo were on by activating his suicide implant. His last moments were happy ones as he received a blessing from Odo. 

Weyoun 7
Weyoun 7 was activated when it became clear that Weyoun 6 was not behaving as expected and expressing feelings that the war was a terrible mistake. Weyoun 6 fled Cardassia and met with Odo, while Weyoun 7 and Damar worked to keep Weyoun 6 from defecting to the Federation. 

Weyoun 7 was killed by Worf. 

Weyoun 8
Weyoun 8 was activated shortly after the death of his predecessor, he continued to oversee Dominion activities in the Dominion War until he was killed by Elim Garak in the final hours of the war. His short life was notable for his suggestion of Dominion mass-murder of the Cardassian civilization, and the execution of orders to do so, up to and including the female Changeling's final order for the genocide of the Cardassians. 

Odo removed the transcorder implant from Weyoun's corpse, hoping the ninth Weyoun would be like the sixth incarnation. 

Weyoun 9
Acting on orders from Odo, Weyoun was sent throughout the Dominion to search for Jem'Hadar who were not dependent on Ketracel-white. He personally identified Taran'atar as one such Jem'Hadar. 

Weyoun 9 told Elias Vaughn that Jake Sisko and Opaka Sulan were alive and with him in the Gamma Quadrant in 2376. 

Weyoun remained close to Odo after the Great Link dissolved in 2376 and assisted him in running the Dominion. During this time Odo worked to change Vorta and Jem'hadar culture for the better, but later focused on individual members of both species, such as Weyoun and Rotan'talag - hoping that both would in turn influence others around them. Due to Odo's influence Weyoun developed considerably as an individual. 

Alternate realities
In an alternate timeline, one of Weyoun's incarnations had ascended to become the kai of Bajor in the year 2400. 

In another timeline, Weyoun was assimilated by the Borg.