Speculations Naki gave the World Haki.

[Dettles]

I wouldn't be surprised if before Nika, nobody could use Haki, but Nika was to one to show his followers how to use it.

 

[gz89]

Nice theory.

Jesus traveled around and taught people about love and forgiveness
Nika (OP Jesus) did the same with haki.

 

[SakazOuki]

So Kaguya but as a main character
That’s one shitty way to create a final arc worse than shinobi war