Valast'aval was Jem'Hadar Second who found himself in a void of the Bajoran wormhole after having been on a Jem'Hadar battleship heading for the Alpha Quadrant in 2374 which was displaced in time and space by the Prophets.

Shortly after entering this realm with his fellow Jem'Hadar and a Vorta, a parasite spawnmother also found its self in the void, the Jem'Hadar went into battle with the spawnmother using their kar'takins (due in part to the disappearance of their energy weapons in the displacement) The fate of the Jem'Hadar, the spawnmother and the many hundreds if not thousands of parasites she contained is unknown. (DS9 novel: Unity)