Slacking My Way to Immortality in a Cultivation World of Strange Tales

Jiang Chen transmigrates to a strange world called the Tianyuan Continent. People here can cultivate immortality, but there's a catch: you have to clear dungeons. Your cultivation only advances after you clear a dungeon with rules, and each person can clear at most eleven, with each one harder than the last. He transmigrated into a woman's body, but strangely, there's another soul inside her, and her cultivation rises by one level every three months.