Sunny and Nephis — and all of humanity, by extension — were racing against time. It was unclear how long it would take to reach the Tomb of Ariel, enter it, and find the key to defeating Asterion inside, so they had to depart as soon as possible.
However, abandoning the Human Domain was not a simple matter.
They knew that their absence would cause harm to humanity. That was unavoidable, considering how dependent everyone was on the two Supremes who ruled the world — one from under the sun, the other from the shadows. Now that the plague of Asterion was spreading like a wildfire, the damage their departure would cause was difficult to imagine.
However, that damage could not compare to the complete annihilation that letting Asterion win would cause. Neither did it compare to the widespread devastation that engaging him in a direct battle would entail.
