Steel-Eating Player is a Manga/Manhwa/Manhua in (English/Raw) language, Action series, english chapters have been translated and you can read them here.
Lee Hyunwook, the steel emperor, was the last savior of mankind, but died. In order to change the future, the place he regressed to was… The military?!! “Why here of all places?!” The start of Corporal Lee Hyunwook, who gets stronger in a special way, by doing a steel mukbang!