I Transmigrated and Somehow Differentiated into an Omega

[Two Male Leads + Not BL + ABO World + Adventure + Fantasy] Li Fei wakes up one day to find that he has transmigrated into an ABO world. To make matters worse, he’s differentiated as an omega and marked by an alpha. He’s afraid his butt won’t survive, and if he goes back, people will probably laugh at him for the rest of his life. To save his backside, Li Fei decides to uncover the truth about this world.