Sunny and Nephis had not been able to battle Asterion in the past because he used humanity as a shield against them. The Dreamspawn settled in Bastion, so if they tried to attack him, a vast swath of the city — if not all of it — would have been destroyed by the ferocity of a battle between Supremes, with countless casualties among the civilian population.
But there were no people here, in the distant reaches of the Glass Hell. The nearest human settlement was thousands of kilometers away, so they could unleash their powers fully.
So could Asterion.
But before any of this could happen, Mordret regarded the Dreamspawn somberly, as if appraising him...
And vanished without a sight.
Almost at the same time, Mordret appeared in Asterion's Soul Sea, having entered it through his golden eyes.
