After I Traveled Through Time and Became the Evil in This World, I Merged with the System

I don't know how to write an introduction. The protagonist at the beginning of this book is a girly, funny, portable grandfather who resembles the original protagonist. That's it, you can take a look if you're interested. The first chapter introduces some settings which may be boring. Some settings may deviate from the original work, so don't worry too much about it. This novel and its characters are purely fictitious. Any similarity is purely coincidental and should not be imitated.