I have an Apocalypse City - Chapter 119 - : Musketeer

Shaymon, the man who has achieved the apex of dark magic, is framed as being a Demon King and is killed.

Light and color, sound and scent;Clothing, food, shelter, transportation, smartphones, computers;Burning, freezing, friction, explosion, thunder, rain, growth, decay;All material changes and chemical phenomena;Our bodies, our thoughts, our world—were all built upon electromagnetic interactions!Whoever could control electromagnetic forces, they would be the tyrant who dominated the world!However, electromagnetism is too profound for us, so let us start by learning how to “Discharge”...

Suo Fei, a veteran NEET has spent three-days and three nights strategizing his way through the highly explicit H danmei game masterpiece “Yalance”. Furthermore, he was able to capture all nine little shous from the nine great races. However, as the final, 10P feast was approaching, he unexpectedly transmigrated. He transmigrated into the real country of Yalance…

Suo Fei: Hey, hey, hey, can you delete these files and let me restart? What the hell did Laozi transmigrate into!

- Description from Novelupdates

Step 1: Inherit a creepy old mansion.Step 2: Unlock a cursed system that makes girls fall dangerously in love with you… just by saying “hi.”Step 3: Learn that if you don’t reject them within 10 texts, something terrible happens.My name’s Ren.And apparently, I’m the “Catalyst for Affection-Based Catastrophes.”(Yeah. That’s literally what it said.)My peaceful new life? Over.Now I’m stuck in a house full of magically unstable girls:A sword-swinging elf.A fire mage with zero personal boundaries.A strict class rep who faints if I so much as look at her.And a witch who cursed the bathroom mirror to spy on me.They’re beautiful.They’re powerful.They’re dangerously obsessed.And if I mess this up, someone’s going to get hurt—maybe me.Reject them too late? Game over.Fall for one of them? Even worse.This isn’t a dating sim.It’s survival of the cutest.Welcome to my life. It's not just a harem. It's a hostage situation.