OMG!
I just realized that of course Vash doesn’t produce anything!! He is basically the cord that connects energy to where it needs to go!! He’s like the doorframe between one room and the next!
(Now given, those roots are definitely some form of production but that only happened when he actually tapped into the higher plan with his full abilities. Outside of that, this man is like an extension cord.)
He carries the energy of either the higher dimension or what he eats (because I’m still convinced that’s why he eats more) to where it is needed, or he connects his sisters back to the higher dimension. And then, because he doesn’t really produce just transfers, that’s why he can end up shooting that large amount of energy because there is no where for it to go except out!
And then in reverse, like all good doors, he can take energy back into which explains the literal black hole this man had opened up.
And maybe the roots/flowers/feathers come out when he has more power then he can handle on his own and basically help with dispersing it or helping it travel. Plus, he’s need to be more plant then human to handle that amount of energy so….
(Or maybe the roots are something else????)