The official Genshin Impact manga acts as a prequel focused on Mondstadt, exploring the backstory of characters like Diluc and Kaeya, as well as the origins of the Fatui. It provides significant lore regarding the city of freedom, featuring characters such as Collei and Dottore, and is available for free on the official game website and Webtoon. You can read the full, official manga on the Genshin Impact website.