Weyoun 6
The Vorta clone Weyoun 6 was activated shortly after Weyoun 5's demise. This new clone proved to be "defective," in that he strongly felt that the Dominion's war against the Alpha Quadrant was a mistake. However, he still maintained his loyalty to the Founders, and therefore contacted Odo, under the guise of Gul Russol, and requested a meeting so he could announce his intentions to defect to the Federation. 

Aboard the runabout  en route back to Deep Space 9, Weyoun 6 explained to Odo not only how he wanted to prevent further conflict, but also how the Great Link had been afflicted by a wasting disease that was slowly killing all Founders, except for Odo. When the runabout was located by his replacement, Weyoun 6 activated his termination implant so Weyoun 7 would call off his attacks, thus saving Odo. The "defective" clone died in peace, with a blessing from one of his gods. ()

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Background information 
Weyoun 6 was portrayed by Jeffrey Combs, in his third of five Weyoun appearances. He was identified in the script as "WV-Six" to differentiate him from his replacement.  

Combs relished the fact he was able to play different sides of his character, later stating, "I remember having a conversation with Ira about how I always fantasized that Weyoun would see the error of his ways and go over to the other side, but Ira's point was that the bad guys are the bad guys. Then we had 'Treachery, Faith and the Great River', which was great; that was about the closest we got to the notion of Weyoun crossing over. I liked that Weyoun." (Star Trek: The Magazine Volume 1, Issue 17, p. 18)

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