The Title of the Book Is About Exchanging the Halo of the Protagonist to Determine Life or Death.

"Welcome to the Halo APP. In the next thirty days, you will spend an unforgettable time with the Halo APP." "Please keep an eye on your? Value." "When the value is around 80%, the system will give users different effects, please check in time." "Use the protagonist's aura to decide your life or death. I wish you good luck."