Level 50 of the Magic Tower: Travel Through the Tower and Become a Shop Owner

I traveled through time and became the owner of the Demon Tower store, and I became the "keeper of the black store" who raised brave men under the Demon King. The king used titles, fiefs, and wealth as bait. The princess was used as bait in prison, and countless brave men swarmed for the powerful and beautiful woman. . . . . . Within the tower, there is no justice, only intrigue. Forming an alliance is false, seizing the treasure is true; Brothers are false, survival is true; Heroes are fake, greed is real. I held the account book and watched with a smile as they fought and killed each other. . . . . . Keeping accounts and selling medicine on the surface, fattening the soul by following the devil's will; Secretly select the strong ones, make contracts, and accumulate the power to destroy demons. . . . . . The brave men fought to the death in the tower, I'm behind the scenes, quietly waiting for the moment to end it all.