"Selling your soul?"
"I do"
You Zheng unexpectedly met an extraordinary... Person on a rainy day? Or the devil.
The devil tempted him to sell his soul
"What an obedient child" the devil's whisper echoed in his ears.
However, there is a price to pay for signing a contract with the devil.
You Zheng reincarnated for life after life in a world where he couldn't tell whether it was reality or a dream, but he never ended well.
This is the price of making a pact with the devil.
"I'll save your soul"
Concept: There is no free lunch in the world