Just a thing: Cronic's a rare case, there aren't cyborgs running around en masse in this little war between the Shinsengumi & Kiheitai ^_^ In fact, the vast majority of people (even the Amanto/Aliens) in the Gintama universe use melee weapons. Strange setup, but it's a nice balance to have. That way it's not like supertechnology vs Samurai-era stuff.

But I like this character idea of yours. Standing between the light and dark, watching everything unfold from an independent point of view. Will he end up joining either side eventually?