I Became an SSS-Class Extra in the Apocalypse

April 1st. Just like a joke, I got trapped in an apocalyptic novel with a grim ending where the protagonist faces the destruction of Earth… And I was just an unnamed extra who dies early in the story. But the keyword #Apocalypse? I actually like it. You see, I’m a psychopathic diehard fan of apocalyptic fiction. The end of the world! The extinction of humanity! That’s exactly the ending I was hoping for! I don’t care what happens to others, so I’ll just find a secret shelter, live a carefree life, and perish along with the Earth! …Or so I thought. [The supreme god Indra proposes a guardian star contract to you.] Decline. Where’s the block button? [Indra asserts that if coffee, he’d be T.O.P, and rank-wise, he’s SSS-grade.] [Indra appeals to your worn-out conscience, saying that with you alone, he can change the ending of destruction.] [Indra……] Ugh, I have no interest in saving humanity, so stop sending me spam emails…! ✦ Moreover, the protagonist, who was supposed to be no-romance and boring in the original, is acting strange. “From here, we’ll go our separate ways. You go save the people, and I’ll go to the shelter.” “…No.” Huh? “I’ll always be by your side.” Huh? It seems I’ve not only received the sponsorship of the SSS-grade supreme god, but also caused the protagonist meant to save this apocalyptic world to turn his back on it. Am I… supposed to take responsibility for this?