Leveling Up By Killing Gods 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

The abyss descends, and the invasion of the alien races begins... The young boy stands amidst the dense white mist, with no light ahead or behind him. In this situation, how will he make his choices? In the era of the Long Night, do the gods truly live forever? The young boy sees through the lifeblood of all things and executes the gods!