Start Leveling up Alone by Solving Strange Incidents

[Ten thousand worlds, time travel, upgrade flow, collection flow, pet flow, pretending to be a pig and eating a tiger, harem? ] One day, the peaceful life was broken, and "doors" to other worlds began to gradually appear in the Blue Star countries. Imps in the forest, man-eating swamps, green eyes in the night, human bones in the grass, giant pythons in the deep pool, black shadows in the clouds, all kinds of bizarre things happened one after another. "My name is Shang Tianyun, an ordinary miserable high school student. A terrible thing happened in my school. The things coming from the 'door' turned into us! My classmates and teachers were replaced by them one after another! I must escape from here, survive! And save this damn world!" This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.