Obvious crossovers that I've seen (and would love to do one day) are Mononoke and Natsume Yuujinchou, but I've had Yamato from Naruto in the Mushishi world in mind for quite a while! So yeah I did that for this prompt instead :3 This little comic is a lot sillier than what I had in mind back then, but I've given up on that idea for now.
Just love the idea of Yamato living in peace with his Mokuton the way Shinra from chapter one does with his drawings that come to life. Not being used as a lab rat or a secret weapon or whatever. Just a man who can make stuff he likes out of wood that grows from his body lol.
Also also lil note: "Adashino would pay a fortune for this" means "Adashino would love this," not "I'm going to try to sell this kind gift to a friend for a lot of money." I think Ginko will want to keep it.