I see a lot of confusion about how lore factors into a Souls’ story.
Game lore is interesting bits of history and backstory that might help to explain how each sub-world (in the game) was formed. The lore may explain why an NPC has been twisted into a monster. Or, it could explain why Blighttown is a poisonous swamp. But it doesn’t have to heavily factor into your Dark Souls character’s end goal/desire: to transcend the Undead Curse.
So, I’ll use DS1 to explain how a story premise works.
The DS1 story spine goes something like this:
A cursed undead is locked up by those who shun her or him; the undead escapes a prison; the undead seeks to escape the curse (and madness) by way of a path that eventually leads to the Kiln of the First Flame; finally, the player must choose to rekindle the Flame or usher in the new Age of Man.
The big story question might be, “Does a fugitive Undead transcend the Undead Curse, ushering in the Age of Man?”
It could also be restated as a story premise, taking the form of a complete sentence: A main character + starting event (verb) + character desire + story outcome.
What lore can do is provide some historical explanations of why something is the way it is now. But don’t force lore to exceed its role in the game. Don’t get hung up on it. And don’t try to work it into your character’s story premise, forcing the premise to accommodate past characters. This is your story. Don’t try to retell the past.