Japanese Warring States Period Inspired Finishes.
This one in particular is inspired by the Ashikaga Clan.

This Series in the collection is a bit different from the rest, which are, to a point, mainly bright and saturated, while these are dull, dirty and old looking. The reason being that the Ashikaga Clan was the ruling Shogunate during that period, but not for long. Over time, like these guns, they became things of the past, their power faded, and other clans waged war for supremacy.