- This character was removed from continuity by his author.
Agent O'Brien was a member of the Department of Floaters, partnered with Agent Van Dyne and later with Chliever the Corroder.
O'Brien, with Van Dyne, recruited Chliever from a Suefic in which Van Dyne was killed. It is known that O'Brien was already a senior agent by this point. After Van Dyne's aforementioned death, Chliever became O'Brien's partner and the two became good friends.
The pair avoided the Macrovirus emergency entirely, but during the 2008 Mary Sue Invasion, O'Brien was slain by a Villain!Sue impersonating Mai from Avatar: The Last Airbender.