After his ship was attacked by a group of renegade Jem'Hadar, Weyoun chose to recruit the assistance of Captain Benjamin Sisko in quelling the rebellion. Weyoun withheld crucial information from Omet'iklan about the rebels' fortress: an Iconian gateway on Vandros IV. However, the Jem'Hadar under Weyoun's supervision remained loyal to the Founders and successfully completed the mission of eradicating the Jem'Hadar rebellion. Following the battle, Omet'iklan killed Weyoun for questioning his loyalty to the Dominion. (DS9: "To the Death")
|Weyoun 4 • Weyoun 5 • Weyoun 6 • Weyoun 7 • Weyoun 8|
According to the script for "To the Death", when Weyoun slaps Odo on the shoulder, he infected him with the virus that presents itself in "Broken Link" and necessitates his return to the Great Link.  This intent wasn't immediately clear in the episode itself.