Empty all along

Last hope

When the king ordered to clean the "abyss" he removed a good amount of the broken skulls of his fallen children.

Hidden in those skulls was the second vessel that was "hollow" it had survived by his own ability to repair his own shell with the power of soul with no actual purpose it just started walking with no direction, no mind, no pain 

Only to be called again to the kingdom when the infection breaks out of the seal and the temple.