The Marshal King

Nobody on the continent hasn't heard of the evil deeds of the great outlaw M. Godspeed. But one day, a young man claiming to be the criminal's son suddenly appears trekking through the harsh desert. This Jim Godspeed says he's killed his father and has the corpse to prove it! A steampunk western from the mind of the master, Boichi!

(Source: MangaPlus)