System, You Want Me to Cultivate Immortality in the Demon World?

"Ding, congratulations to the host for obtaining the Immortality Cultivation System!" "The Immortality Cultivation System?" Lu Ming was overjoyed. Before he could react, the system's voice rang in his ears again: "Ding, the system detected that there was a deviation in the crossing position. In order to compensate the host, a guardian beast will be rewarded. Please check!" Then, a husky appeared next to him. … Lu Ming was bound to the Immortality Cultivation System, but due to an accident, he did not travel to the world of immortality, but came to the extremely dangerous demon world. From then on, Lu Ming and Erha began to live in fear from the demon world.