Call me crazy, but the first person I thought of when reading through this violent cheesefest was Tetsuya Saruwatari. I saw the rampant crazy gore, the vague political background of the story, the seemingly invincible protagonist, and all I could think was- "Wow, this must've influenced Saruwatari even more than Hokuto no Ken or JoJo's did." But low and behold, that's not the case.
This manga was released in 1997! Many years after Tetsuya's more violent works were published, and I think we have a different happening here: It is very likely that the same man influenced by Hara, ended up influencing Hara in a big way, at least here. I haven't read many of Hara's younger works, but I'll just have to mention it as I see it from now on and see if my idea holds any weight.
Pretty good and fun for the few chapters it's got, I blazed through em without much thought or pausing, other than to look at all the insanely good art. Would recommend for any psychoviolence enjoyer.