it is a group of pure spirits of light sent on mission from high above to rekindle the fire of the world.

in their mission they first have to redeem/wake an ancient sleeping dragon at soul level.

when the dragon wakes they have to choose either the death of the body or to renounce the purity of their soul/sacrifice the dragon instead.

in choosing the latter they redeem the dragon and they become the nobody.

although it is more an awakening to the fact that they always have been nobodies and allsouls. just that for a time they tried to fool themselves that they should be somebody, like everyone else.

afterwards the process of transmutation commences, the dragon/soul is infused in the infinite source of spiritual light, until it reaches full power.

then the highest possible form of magic/sacrifice is achieved.
the dragon/soul becomes the Nosoul, shattering itself in myriads pieces of light that will rekindle the spiritual fire of all suffering souls.

it return to the form of pure spirit and goes back to the Source.