The Doom Of Valyria mystery

[Pontius Pilate]

It's ancient history within the history of Earthos.  It's caused by people playing with fire and it got out of hand.  Maybe the First Men played with dark magic back in the past and that's what created the white walkers.  The Starks wanted to create super soldiers for their war with the other families and the white walkers are the fruits of the experiment.  Maybe the Starks are not as backwards as we are led to believe.  

[Kobb]

9 hours ago, Centurion Piso said:

It's caused by people playing with fire and it got out of hand.

Though this doesn't explain what role the Faceless Men might have played, if this quote is to be believed:

Quote

That very night he chose the most wretched of the slaves, the one who had prayed most earnestly for release, and freed him from his bondage. The first gift had been given." Arya drew back from him. "He killed the slave?" That did not sound right. "He should have killed the masters!" "He would bring the gift to them as well . . . but that is a tale for another day, one best shared with no one."

I certainly think it's in part a Khazad-dûm style "delved too deep" situation, but I also can't imagine that's all there is too it. Perhaps the Faceless Men indirectly incited the turmoil that led to collapse of the sorcerers who managed the Fourteen Flames.

[H Wadsworth Longfellow]

On 4/30/2019 at 8:34 AM, rotting sea cow said:

Very possibly a combination of all. The Valyrians were sacrificing to powers they didn't understand and these poweres grew hungrier and hungrier to the point of instability.  The infighting among the ruling families prevent join action against that. At the same time the faceless men were killing key members, fueling the said infighting and weakening Valyrian magic,

 

 

The followers of the red god do human sacrifice.  Cooking is more an apt description but they fed people to their flames.  Whether the Valyrians were doing the same is up for discussion.  We know the First Men and the Starks did it in the past.  The mirror reflection of the First Men are the Valyrians.