I first played the Demon's Souls remake a couple of years after it had come out. All through the first couple of worlds I ran, I would often notice the same ghost player (based on their appearance) basically in lockstep with me, we seemed to be on the same schedule for when we played and progressing through the game at the same pace.
I've always wondered whether seeing a ghost player in Souls games means that they can also see you at the same time. I hope you can because it was just deeply satisfying to feel like I was in the same game as this stranger from who knows where, a silent companion exploring this deep, dark, dangerous world alongside me.