During the Imperial storyline for Onslaught, the player character is tasked with eliminating Anoser and Anosek in an attempt to infuriate King Regalun Petryph into rallying his supporters against the Republic in an attack on the capital Iziz so he can reclaim his throne. The player character can either kill them both or take them as prisoners.
While the fates of the cousins are not detailed during the Republic storyline, Lana Beniko brings up the idea of the cousins being potential replacements for who becomes ruler when Petryph is deposed, but laments that they aren't proper material for such a role.