Rental Hero is a Manga/Manhwa/Manhua in english language, ACTION series, english chapters have been translated and you can read them here. You are reading chapters on www.mgeko.cc fastest updating comic site. The Summary is

Lee JooWon is a doppleganger who works for heroes by taking their place while they’re out saving the world. He is approached by Justice, the number one ranked hero, who hires Joowon to replace him. After agreeing to Justice’s offer with a hefty compensation, Lee JooWon goes to the agreed-upon location and sees something he never expected…