The Reborn Otaku's Code of Practice for the Apocalypse - Chapter 3

A lonely soul, which was placed under the care of the Lord Protector’s Manor, ended up having her lover stolen by the family’s eldest daughter and dying tragically the day before her wedding.

Somehow, she was reborn in the family as their 14-year-old first wife’s daughter, Ning Xueyan, with a startlingly familiar face.

Step by step, she will ruthlessly scheme to seek revenge as well as uncover the mystery of her tragic death.

Her former fiancee, the flirty crown prince and the bloodthirsty prince, will now bear witness to a vengeful Ning Xueyan becoming the peerless lady of her generation…

- Description from Novelupdates

____this story sets in Japan that developed a little different history from yours.

This is how a Japanese Princess relieves her stress of the day by using the latest VRMMORPG, and while playing the villain there, the first town turns into whirlpool of chaos, smashed the underground organization in one hand and went for a coup. It’s literally a playtime diary of a girl who is called as “Genocider-san”, “Roaming Last Boss”, “A different person plays the game”, “Raid Boss”, “Ruthless”, “Calamity”, and such by the players.

I opened my eyes to find myself in another world. For some odd reason, I ended up as a sword. Before my eyes laid a plain full of magic beasts, and so, I launched my body and flew in search of a partner, a wielder (females only). Wait. Absorbing magic stones gets me skills? Oh hell yeah! This be fun! More, more, give me more! Gimme all your magic stones! Okay, yeah no, but I am accepting anything anyone’s willing to give. This tale is one that follows your everyday nerd, normal as could be, save for the fact that he happened to reincarnate as a sword.