Drawing Cards with My Lifespan, Am I Out of Balance?

The world is one enormous gacha pool. Yin Mingxi unexpectedly gained a special ability: as long as she is willing to spend her lifespan on a "pull," she can get anything she wants. But just as she was eager to give it a try... [Available lifespan: three years] After seeing the steep cost of one pull per year to start, along with odds about as good as finding a needle in the ocean, Yin Mingxi, who had only lived sixteen years, quietly put the idea aside and decided to enjoy the peaceful life she had left. Until one day, a classmate who had always seemed completely unremarkable showed her a strange phone app and said something even stranger: "Classmate Yin, from now on, you'd better be a good girl and do as I say." Yin Mingxi: "?"