"I am an omniscient and omnipotent goddess. I can grant any wish you make~"
"I want world peace."
"That wish would affect the course of the world's evolution. Pick another."
"How about solving the Yang-Mills existence and mass gap problem?"
"..."
"How about resolving the incompatibility between general relativity and quantum field theory?"
"..."
"How about proving the Riemann hypothesis? The Goldbach conjecture?"
"..."
"Goddess? Are you still there?"
"Let's talk about world peace after all."
(No cheats, a little angst, and the impact of a transmigrator with cheat abilities, seen from the perspective of the locals in another world)