Emperor's Mark to Rule the Monsters: Reborn Sage to Strongest Adventurer is a Manga/Manhwa/Manhua in english language, Adventurer 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

Emperor Ludis suffered an unjustified death because of his Emperor’s Mark, which allowed him to make servants out of monsters. But instead of dying for good, he reincarnated a thousand years into the future. His previous life gave him no freedom, so this time, he’ll take it all and travel the world as an adventurer! But although he pretends to be normal, he gathers servants again and becomes the strongest adventurer! Come see what adventures await Ludis in this monster-filled isekai fantasy!