Possibly because the Awoken are made from both the Light and the Dark: the Light is near death, and the Dark is death

Also, a. It of a strong theory, SKYSHOCK was the alleged traveller's push back of the darkness, it was a shockwave of light. Rasputin hadn't enough light, so he deactivated his moral codes and harvested human souls for it-as you know, the awoken were the humans who were fought up in this shockwave. The two souls were the originals and the light ones.

I believe it's more along the lines of Rasputin bid after the first encounter with IT at the edge of the system. He watched as it ravaged both humanity and the Traveler, and he came to a realization on how to beat the Darkness. With help from some of the Traveler's last Light and antimatter bombs in the Reef, he blew the Darkness back. Skyshock is the name of an important defensive array in the Cosmodrome, nothing more