I think I'll be writing up a wandering Kusagi swordsman, then.

Is it fine if I write in stuff for the culture of Kusagi? For instance, it was my idea that the people of Kusagi worships spirits as lesser gods, enshrine them and pay homage to them. Families would have "house spirits" bound to their bloodline rather than specific individuals, with more influential families having more or more powerful house spirits.

Is it possible for spirits to be related to each other? Something I was considering for my character was to have him bound to a Gargantuan, and then several Humanoids that are the Gargantuan's "children."