Canonicity of Sandman: Endless Nights

[literally exaggerated]

In the 3rd story in Endless Nights, Dream's gf Killalla is an inhabitant of the planet Oa and is working on mystical techniques to manipulate green energy, Despair talks to a red star named Rao about the creation of life on an unstable world and the possibility of a lone surviving being existing to continually mourn the destruction of that world.

Is this DC canon? Is that the origin of green energy manipulation and an example of what the ancestors of guardians look like? is that the soul of Krypton's star, and if so, is little Sol the true form of the sun in DC?

[Bat-Mite]

Is this DC canon?

Sure, why not?

[Forsaken_One]

It's cannon right up until someone says it isn't.

[Alan2099]

It's cannon right up until someone says it isn't.
And even then, it can be seen as a Dream.

[palaeomerus]

I thought that the original power batteries were made on Malthus before the Guardians evolved to have big heads and went to Oa at the center of the universe.

They never wrote any stories about my favorite of the endless...Dyspepsia. (She causes chronic stomach aches...)

[Aaron King]

Those aren't people, they're stars. That isn't someone from Oa. It's the personification of Oa's sun, just like Dream is the personification of dreams.

[literally exaggerated]

Killala wasn't, she was specifically said to be an inhabitant of Oa, and was blown away and shocked by meeting the stars.

Its significant because it establishes the origin of the green lantern energy, i.e. this mystical/spiritual energy which anyone can learn to manipulate and which stars and other high-level entities seem capable of innately controlling on the scale of a pretty powerful GL, at the very least.

It also means the the sun of DC earth is an actual, sentient entity, and so w as the sun of Krypton, and they new each other, and also that the sun of Krypton seemed to have some foreknowledge of Superman's existence.

Not directly integral, but potentially important.