Board Thread:Dark Souls II/@comment-24494913-20140319193521/@comment-174.67.222.101-20140613042147

There are not one but many bone dusts. It tells us that this has happened many times before. Kingdoms rose and fell.

As the Dark souls game states, after the age of fire, the age of dark goes in and the curse begin. The curse  only shows up when the fire is fading, so that a chosen undead can gather souls and reignite the flame. As shown in Dark souls 1, u can either link the flame or let the age of dark continue. If you let the age of dark continue, another chosen undead will link the flame. If you link the flame, age of fire begins and the undead curse is gone but only for a little bit until the fire fades and the curse appears again for yet another chosen undead to reignite the flame from the ashe.