Ruler Of Mathematics

Alternate Titles: Rational Villain In Another World

After defeating the fallen strongest hero, Hugo Barnett retires from his villain work while suffering from depression due to killing the person he loved the most.

"But it is the most rational thing to do..."

Hugo mutters as he contemplates his past action, thinking whether he did a rational thing or not.

Locking himself in a room, he resolves himself to erase his existence in his world to fulfill a promise he made before killing the fallen strongest hero. Dividing the distance by zero, Hugo has created a portal that will lead to a place with unknown probability.

"Fulfilling a promise is the most rational thing to do."

Hugo says as he enters the portal.

Little did he know, the portal leads to another world where irrational wizards chant their spells (irrational since telling what your spell is equivalent to telling your opponent what you will do.) and monsters that can destroy the world invades the world.

How can he survive in a world where danger is the norm while choosing the most rational decision?