My Rebate System Is Actually a Tiandao Private Account

[Traveling through the fantasy world, Lin Xuan became a shabby shopkeeper with no qualifications. When he was about to starve to death, he was bound to the "karma rebate system"! If you give someone a broken sword, you will get back to me the secrets of magical skills; if you invest in a down-and-out genius, you will get back to me a peerless cultivation level. He thought it was just a Tiandao BUG, ​​but he discovered that this was actually a private account that Tiandao used to repair the loopholes in the world! Since then, there has been a mysterious shopkeeper in all the worlds: Kung Fu, magic elixirs, magical weapons, secret realms, all can be invested, and no one can be deceived. Let's see how Lin Xuan "invests" with one hand, leverages cause and effect, stirs up the world, and becomes the biggest trader behind the scenes!