I'm Studying to Become Immortal in a Mental Hospital

Seven years ago, the earth was hit by a mysterious force, causing frequent tsunamis and abnormal climate. It has been weird ever since. Ding Ling was 12 years old that year because he insisted that he saw a white dragon swimming out of the bottom of the lake. Then he was imprisoned in Ward 301 of Jiren Mental Hospital with five other patients. Each of these five patients is a talented person, and they actually teach him to cultivate immortality every day! Ding Ling thinks their condition is very serious! But one day, a crack suddenly appeared in the sky above the mental hospital. Strange creatures appear one after another, and killings continue...