Starting with a Sign-In, I Flatten the Dark Calamity and Become an Emperor

He transmigrates to the Chaotic Ancient Era. He binds himself to the Heavenly Emperor Sign-In System. Killing dark creatures lets him continually increase his cultivation. A dark calamity erupts from the start. Must he hurry after the Desolate Heavenly Emperor and leap into the heavens? Liang Zhong, who missed his chance to ascend by a single step, is bewildered. Fortunately, in this world, he can sign in anywhere to claim rewards. Sign in at the Kunpeng Nest and receive the reward: [Kunpeng Treasure Art]! Sign in in the Void God Realm and receive the reward: [True Phoenix Treasure Art]! Sign in in the Foreign Realm and receive the reward: [Immortality Secret Art]! Sign in at the Bronze Coffin of the Three Ages and receive the reward: [Great Luo Sword Embryo]! To ascend to the heavens and fight alongside the Desolate Heavenly Emperor, Liang Zhong proceeds with utmost caution, traversing the whole world and signing in for ten million years! He swears he will never emerge until he becomes an Immortal Emperor! Then, ten million years later, a Dark Immortal Emperor is born, and dark creatures launch a massive invasion. The Nine Heavens and Ten Earths are in peril! With the Desolate Heavenly Emperor having taken many peerless experts with him before departing, the entire world is plunged into darkness. The greatest Immortal Kings are even slain on the Dark Continent. Just as the world crumbles and the Great Dao mourns, Liang Zhong, with the True Dragon Treasure Art in his left hand and the True Phoenix Treasure Art in his right, raises his hand and summons the Desolate Heavenly Emperor's Great Luo Sword Embryo. One peerless sword strike later, the Dark Immortal Emperor is dead! Only then does he suddenly realize that he has become invincible in the world...