Amaterasu is flames stolen from Hell itself.

[Booker]

Spoiler

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This is the King of Hell. Notice anything interesting surrounding him?

Yep, black flames. Not too different from a certain Uchiha technique...

Could it be that Amaterasu steals the black flames of hell, and spawns it on the target?

 

[Aya San]

Yet it's only gravel to Maddy

 

[Mitarashi]

Those flames weren't "Ever burning".
They went out lol.

 

[Ganta]

where is stated that the statue thing (forgot the name) is from hell?

 

[The Sach]

Yes they are.U_U

 

[SpiderRider89]

Spoiler

You must be registered for see images

This is the King of Hell. Notice anything interesting surrounding him?

Yep, black flames. Not too different from a certain Uchiha technique...

Could it be that Amaterasu steals the black flames of hell, and spawns it on the target?

The Rinnegan is the evolution of the Sharingan so I'm not that surprised.

 

[Sir Blades]

They look like amaterasu flames, but it didn't look like that in the anime.

 

[Meee]

Nah its stolen from Yu Yu Hakusho XD