Vagrant Lore?

Is there any lore at all behind vagrants? I've been wondering about this for a while now. If not, then does anyone have any ideas about them or want to speculate?

Apologies if this has already been asked...

They always kind of seemed like a wasted idea to me. No lore behind them, incredibly rare, and no good reward for finding one. A great idea, horrible implementation. Unless the whole point was to simply add a strange chance for a WTF moment, in which case it still wasn't that good.

Ive always seen them as a gameplay element that comes around when theres a bunch of people disposing of unwanted items, much like those rings that appear when people are casting miracles (and the general interactivity that high Faith based characters enjoy while in online mode), it is interesting to see that there are "good" and "evil" versions of them though.

I think From Software has stated repeatedly that they wanted to add a degree of unpredictability to the game. Originally, the Black Knights were meant to be enemies that wandered around, rather than just staying in one spot. Perhaps the Vagrants were a carry over from this. It's a way of adding surprise to the gameplay.

Aliens!

I don't know. I would like to think they're the manifestation of others suffering though. It does fit with their purpose, so yeah.

Who knows. They could just be black phantoms, like Mildred or Kirk. Just, rather than a lore background, they have a game mechanic. Like, maybe they're supposed to represent actual people invading us, but we just don't know who they are.