Don't Fall in Love with a Doomsday Maniac, You Have to Pay More

I was reborn three days before the apocalypse broke out. In my last life, I was pushed into a zombie swarm by my most trusted brother and girlfriend. In this life, I awakened the SSS-level ability "Equivalent Exchange". They knelt outside the safe house and begged me to take them in: "For the sake of the past..." I smiled and activated the system: "Okay, but what will you give me in exchange?" Looking at their frightened eyes, I knew that in this life, even breathing would be charged.