So, I have an idea of a destructive cult in a dark fantasy novel/manga

I'm planning to become a writer, and I have an idea for a cult in grimdark dark fantasy setting where evil empire tooked over the continent. Due to how oppressed and enslaved people's hopeless situation I bet they will develop a new religion based on suffering and masochism. Let's say, for them suffering becomes a meaning of life, and believe this world is made for suffering. They endure suffering and even do harm themselves mentally and physically. They worship to suffering. What you think?