[Theory] Sword of Nunoboko.
I'm just going to jump right into it, i'm not really good in making theories but here i go.
When Obito pulled out the sword he said that its the sword that the SO6P used to create the world.
And by logic, its obvious that that isn't the truth.
As we've seen, the black stuff that Obito used earlier, can basically cut through anytime, precisely.
The sword, also looks like its been made out of the black stuff that Obito uses to attack and protect himself.
And...... as we've seen when Hiruzen threw shurikens at Obito, the black stuff was able to disintegrate it precisely.
So i have to a conclusion that the sword of Nunoboko was used to ''carve'' the landscapes to the SO6P's likings,
rather than ''Creating the world''