why would Henry want to forge a grossly inferior weapon and armor that's on par for what his ancestors made 400 years ago? Besides, there's no peasant rebellions in the game for him to squash to effectively be what a samurai was.

Weebs gonna weeb.

Katana could easily function as a sabre, though, for 2-handed feels silly due to how short they are. A tachi or odachi, makes more sense for the time period, early Sengoku.

Samurai armor would basically be lamellar with falds, though from pictures they seem to use larger lamellar plates that the ones in KCD, so you'd have to make new models, perhaps.

Helmet would just need a kettle helm with a face mask.

There's a katana pack on Nexus but I haven't found any samurai garb.