Kami-sama no Memochou - Volume 8, Chapter 1

Solomon woke up from surgery to two revelations:First: His girlfriend had been cheating on him with a B-Class citizen.Second: She'd sent people to kill him.As assassins closed in, a voice spoke in his mind:[SSS-Rank Cashback Billionaire System Activated]Solomon had seconds to live. No time to think. He offered his killers everything in his account $10,000 to spare him.[Transaction complete. Cashback:$50,000]The system didn't just save him. It gave him infinite wealth. Every dollar spent returns five hundred times over.But power came with a price.Solomon was drafted into the Dimensional Wealth Trials—a multiverse death game where twenty thousand players fight across infinite worlds. Only one hundred will survive.Cultivation realms where humans are livestock. War-torn kingdoms soaked in blood. Alien planets with horrors beyond comprehension.Solomon isn't strong. He isn't fast. He isn't a fighter.But he has something no one else does: unlimited money.And in worlds where everything, survival, power, even fate, has a price, the richest player always wins.Cold. Calculating. Ruthless when necessary.Solomon will buy his way to the top.Or die trying.SSS-Rank Cashback Billionaire System: Building Wealth!In a multiverse where everything can be bought, the poorest boy becomes the richest player.

When she woke up, Lake returned to the classroom of the third year. The classmates were in class with swords and sticks, and the teacher became a female Taoist.
The little fat man in the back seat, how to put two big hammers under his chair.
Rick found this to be a global era!

- Description from Uukanshu (translated)

Thrown into his favorite novel as a powerless extra, he never expected to survive, let alone tame the gods.In a world where strength is everything, chaos reigns and beasts roam the land, including fearsome dragons and gods, the stakes have never been higher.With the power to tame beasts that even gods fear, he must rise above a world on the brink of collapseBut how will he fight for his place in a doomed reality!