MTL - Being Reborn And Starting Off By Not Being A Simp - Chapter 15 click till

As the ruler of a munitions empire, Tang Mo unexpectedly fell and was transported to an entirely different world, where he also unexpectedly acquired a “King of Munitions” system.In this underdeveloped world, Tang Mo relied on the abilities granted to him by the system to drive the development of the entire world.After all, the desire for civilization conquest had always been the driving force behind progress, and life had continuously evolved between attack and defense over tens of millions of years...So, selling assault rifles to these archers and training knights to be tank operators... there shouldn't be any problem with that, right? XD

Based on the popular Vocaloid series, by HoneyWorks, called “Kokuhoku Yokou Renshuu (Confession Rehearsal)“:

Natsuki, a third-year at Sakuragaoka High School, who holds unrequited feelings for her childhood friend, Yuu, who’s in the Film Club. However, instead of being honest about her feelings, she makes him be her confession “rehearsal” partner. Unable to say her true feelings, things start to get complicated when Miou and Akari, who are also in the Art Club, get involved! Will she ever be able to confess for real!?

Unhindered in the Demon Domain, the king is solitary!

In the world where immortals and demons strive, a good natured fellow sought the Demon Dao in search of justice.

At the end of his journey, he had eventually become this generation’s Heavenly Demon Emperor.

Although I am not fond of slaughter, I do not dislike it!

Desiring to see the Demon World, this is how I strive, this is how I become the Peerless Demonic Lord!

- Description from Novelupdates

She, the “godly doctor” of an assassin organization in 21st century, transmigrated into the body of Yun Family’s abandoned, good-for-nothing Ninth Miss. Good-for-nothing? Then she’ll let the world see what a real good-for-nothing looks like. Summoners are legendary? Nothing is impossible in this world! She’ll become the first Magical Summoner.

He, the third prince in Long Xu Kingdom and the mysterious, behind-the-scenes owner of Zhou Dynasty’s monopolized business, seemingly handsome and uninhibited, is actually brutal and merciless.

The world knows her as a sickly good-for-nothing and her standing is as low as a servant’s, yet she solely dominates his heart. Trickery, schemes, overbearing, seducing… an exhaustion of methods, all to capture her heart. The scheming couple supports each other, producing stories about enmity, love and win-win cooperation.

Read to see how they stand side-by-side at the peak of this extraordinary world.

- Description from Novelupdates