A 0.0000001% Demon King is a Manga/Manhwa/Manhua in english language, Manhwa 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

The 72 Demon Kings, who received the order to destroy the earth, each went through a trial by the Great Demon King Astrea. Those who passed the trial earned the title of Demon King, and each Demon King was granted special powers by the Great Demon King. So far, each Demon King had been granted extraordinary abilities. When Karos became a Demon King, he received a power from the Great Demon King, but… “Great Demon King, no matter how much I think about it, there is a problem with my power.” “Problem?” Among the Demon Kings with extraordinary abilities… Karos received the “Gacha” ability. “Gacha as the power of a Demon King? How am I supposed to rule the world with Gacha?!'”