There is nothing to fear from the darkness, it is in our nature as humans to assume that what we don't understand could hurt or possibly kill us. The traveler came bearing gifts of advanced technology and wisdom which we in turn took to mean good things about the traveler. Our imperfection as a species means that we have faults, and faults lead to mistakes, mistakes lead to our understanding as a species, to not seeing some evils even when they're right under our noses. Our fault is letting the Traveler into our home after knowing nothing about it and taking its "gifts". Our fault is accepting one side of a story without hearing the other. Our faults cannot be erased from history; our faults cannot be undone. Our faults will be our undoing, for there is nothing to fear from the darkness, the darkness is the side of the story we haven't heard, the darkness is a name humans have given something unknown and unseen be us, it's motives and all are unknown to us, only that it has killed the majority of the human race, but for what cause. The cause is siding with the "traveler", our undoing, our God, our hero, a hero that armed us to the teeth to fight the "darkness" when it came to kill the "traveler". Our faults cannot be undone, it is who we are as a species; we have brought our own death upon us, oblivious to it for so long. But a side must be taken, even if it's the wrong side...