What the hell is making games in the Ninja World?

Uchiha Kai: “I’m a unlucky guy who traveled to the ninja world, and the system turned out to be a scammer used to make games and train me to be a super game producer. What suffering in the world!?”
System: “After testing, this is the earth in 2024. Host, please complete the production of the first game as soon as possible.”
Uchiha Kai: “Okay, okay, you want to play it this way, right? Okay, since I’m not having a good time, then use the Uchiha way to make the world feel pain!”
“Hell game, start it for me!”
From then on, the ninja world had an old thief Uchiha who used the Sharingan to make the underworld game to take revenge on the world.