The Void Ocean refers to the realm of immensely large cosmic voids that resulted from the mass destruction of galaxies during The Devouring of Heaven.
The Void Ocean is named as such as starlight has been all but extinguished from such realms, and it is believed that any remnant galaxies within the Void Ocean are in a quiescent state, only harboring corpses of dead stars.
Only the The Grand Expanse was spared from The Devouring of Heaven, as a dark galaxy that exists within the epicenter of a cosmic void that bear the Artificial Void Sun of Isame of a Thousand Eyes.