I read a post that had a theory a while back that I personally enjoyed, so I'll put it here, but I'm not claiming it as my own theory. Basically, the traveler and the darkness are both these god like beings who have been battling for millennia. The traveler has been on the defensive for centuries and is running out of options. So the traveler starts giving its power to different species it encounters and/or creates in order to defend itself. Though no species has been able to stand against the darkness, and as a result the species are corrupted and enslaved by the darkness. But then something remarkable happens. The traveler finds a young planet, but with so much potential. He sees the good and wants to help it grow into a strong, powerful planet. So he gives them his technology, tells them his secrets. Shapes this adolescent planet into force to be reckoned with. But he runs out of time. The darkness catches up with him. As a result, all of his work is destroyed. But there is still hope.... He sacrifices himself to save what little of humanity is left, and buys them time to rebuild and bestows one final gift to this planet.... Light. With this light, this planet may just survive. With this light, humanity becomes..... Legend