Board Thread:Theories and Speculation/@comment-1512913-20161119171442/@comment-1512913-20161119175013

Guess either few people thought about it like that or bothered to discuss. Bloodline Selection, if it's really supposed to mean in the context what I think it means, suggests that the genes required to mix Fire, Earth and Wind natured chakras into Dust, came to be my merger of two or more different genomes with special genes.

So maybe by breeding an individual who has genes for Lava Release with someone who has genes for some other advanced/combined nature transformation, Dust came to be.

Maybe that's what it meant that secrets of Dust Release were passed down onto Onoki from Mu, it can mean the knowledge how to produce a Dust Release user by selective breeding.

EDIT: since the canon shows it's possible to combine 3 natures into 1, I don't see why more combinations wouldn't be possible, like combining Water, Lightning and Wind into an X Kekkei Tota nature as an example. No specific ideas right now of what the others could be and do though.