Monsoon - metal gear rising revengeance by watanabe1 on DeviantArt
In the files of the demo version of Metal Gear Rising: Revengance, there exists a file of a model of monsoon where his mask is broken. This implicates that it was originally
monsoon (metal gear and 1 more) drawn by 7gou | Danbooru
Metal Gear Rising Revengeance Monsoon" Sticker by Zero . | Redbubble