After Impure World Reincarnation, I Became a World Bug

God said: I am the only perfect existence in the world.

And so, after He was born, the originally flawless world acquired flaws.

Humans, standing above the myriad species, discovered these oversights and called them the world’s bugs.

Bug 1: Wish-granting spell

Write a wish on paper, and at the moment when day turns to night, fold the paper nine times.

When it is unfolded, if the writing on the paper has disappeared into yesterday, the wish will come true in the new day.

Bug 2: Karma conversion spell

Bug 3: ...

Bug 4: Dirty-blood reincarnation

Bug 5..., ..., ..., Bug 13.