Okay, I've never played the table-top game, but I do enjoy reading the lore and the TotalWar adaptions. So, we know the Old Ones were the first to use magic, constructing the gates at the poles to allow transport between their home world/planet, and the world of Warhammer, they were also predisposed to Order, having uplifted Men, Dwarves, Elves and Lizardmen etc. all of whom (for the most part) favor Order. The destruction of the gates was what resulted in chaos spilling forth initially, so when the gates were first set up, even if Tzeentch or Slaanesh wasn't formed, Nurgle almost certainly would have been, likely Khorne as well. The Chaos Gods want to rule, or unmake reality, or merge their world with the material, but all their focus is devoted to the Warhammer world, why do we hear nothing of where the Old Ones came from being over run with Chaos? When the Gates fell, and the Old Ones vanished, did their entire star-spanning empire fall as well? If so, how has the Old World not be inundated with creatures loyal to chaos traveling through the Aether from other worlds, alien Beastmen and similar? If that isn't the case, why are the Four Brothers so interested in the Old World? I know it's likely a question that boils down to "because we need a pretext for the game dammit" but I'm curious if it's addressed.