The Demon Lord's Dilemma

【Two male leads + Demon Lord + transmigrate into a book + one-on-one + villain + two powerful leads】When Xiao Chenyi transmigrates into a book, the System tells him that his mission in this life is to be killed by the protagonist, after which the protagonist can carry on being the protagonist and Xiao Chenyi can return to being a movie star. “No problem, I know this drill,” Xiao Chenyi assures it. “I’m grateful to the organization for giving me another chance at life. I’ll complete the mission properly. If the protagonist can’t beat me, I can always slit my own throat.” System: “...Don’t get too cocky.” Ten years later, all that remains before the protagonist can achieve success is killing the Demon Lord and uniting the realm. That day, Xiao Chenyi puts on a rare white robe, thinking the blood-red sunset will make for a suitably heroic scene. The protagonist unsheathes his sword. Xiao Chenyi wipes his neck, swallows, and takes a step forward. Then the protagonist sets down his sword and draws a dagger. Yikes. A chill runs down the back of Xiao Chenyi’s head, and he takes another step. The protagonist raises the dagger high Xiao Chenyi closes his eyes, ready to die heroically. “Clang!” The sharp ring of metal striking metal makes Xiao Chenyi open his eyes. He looks up in surprise and sees the protagonist staring in disgust at someone behind him... “Why have you come to see His Lordship again?” Behind Xiao Chenyi stands the famous Immortal Venerable of the righteous path, immaculate and unsullied. Xiao Chenyi: “...” You old bastard, blocking my path to death. I’m going to pull out every flower on your mountain. Xiao Chenyi leaves the Demon Realm in dismay, ignoring the two big shots already fighting behind him. He’ll die another day. Once again, once again, he can’t manage to die today.