system
Given the following post, respond as if you're commenting on Reddit:
human
[Dark Souls] Where are all the other undead champions?

I busted out of the Undead Asylum and this guy near the bonfire told me many had come before me to try to do whatever I'm supposed to do here, but aside from a very small handful of delightful weirdos, all I've seen are undead natives. If they all went hollow, where are they? We can't die permanently, so shouldn't they still be shambling around somewhere in Lordran?
gpt
I believe they're the other players. As the sun guy mentions, time's gone a bit wonky and him and you are doomed to kind of randomly fade in and out of each other's reality and the ghostly images of other players sounds a lot like that almost happening. 

This can be circumvented by summoning like with the white soapstone he gives you and, wouldn't you know it, that's exactly how you initiate co-op.