Erich did not stay on Svartalfheim to celebrate. No, there was no time for his victory over an ancient and lurking evil. Rather, he was forced to contend with a far greater threat, here and now.
With the darkness that had shrouded the original elf homeworld for close to a million years having disappeared without a trace in the span of a mere second, the nearby Naraku who had been stalled at bay, fearing the shadows that could and would corrupt them instantly began to attack in a feeding frenzy like a school of piranha who smelled blood in the water.
But for them to do so, meant that they would have to first break through the line of defense which Erich had established around the system when he invaded, and seized control of orbit. Put simply, the Naraku and their biological efficiency were forced to contend with the surgical precision of ships controlled by artificial intelligence and robotic crewman.