Wikipedia
Grimjack is the main character of a comic book originally published by the American company First Comics. John Ostrander and Timothy Truman are credited as co-creators of the character, although Ostrander had been developing Grimjack with artist Lenin Delsol before Truman's arrival on the project according to Ostrander's own text piece in Grimjack #75. In that same essay, the writer also revealed having initially conceived the character to be the star of a series of prose stories, set in a post-apocalyptic Chicago.
Grimjack is the street name of John Gaunt, a sword-for-hire, ex-paramilitary, war veteran and former child gladiator. He operates from Munden's Bar in the Pit, a slum area of Cynosure, a pan-dimensional city to which all dimensions connect.