[ Knives nods solemnly at his younger self's question -- yes, their brother, the older version of Vash with his black hair, is dying. His condition is terminal. ]

I can only tell you what I have tried, in my efforts to keep him safe. [ He rests a hand gently on his younger self's shoulder. ] I hope you are able to learn from my failures.

[ Yes, this is precisely why he is here. Not only can he point this other version of himself in a direction to keep Vash safe, but this young Knives has the opportunity to save all the plants on Noman's from their human captors. He can only hope that Vash hasn't yet told the child too many lies about humanity. ]

The Vash I know cannot stand to see others suffer. His is a kind, gentle heart. I assume your brother is the same?