My Genius Sister is Only Seven!? - Chapter 30

A story of time-travel. Sly and cunning, she unexpectedly became a sickly noble lady whose fiancé is merciless and demotes her to a lowly concubine. She sneers and bravely breaks off the engagement. To hell with scumbags, marry heirs to lords, blind the courts with her brilliance.

Akira Kuromiya is just an average high schooler who gets killed by a robber. He wakes up and is now a chicken!? Even worse he becomes the familiar of a girl who's apparently the heiress of a powerful clan.

That was for a short while though, as he was abandoned and woke up to find out he, now she, is trapped in a deadly magical forest with all sorts creatures trying to kill her.

The world she finds herself is one of magic and monsters like the manga she's been reading. Akira, now Hinotori is trying to live her life as a chicken in another world!

With the Legendary Mechanic System, I transmigrated to Marvel Universe to be Dr. Zola’s assistant.

With Mechanical Force Analysis, I can learn every black technology.

Winter Soldier’s arm? I built a better one for you.

Iron Man’s armor? I already made it a decade earlier.

Doc Ock’s tentacles? I am the one who provided core technology.

Hulk’s mutation? Sorry, I was there and got hit by the radiation too.

As for a certain purple potato, can he collect all Infinity Stones?

……

However, I only had one simple ultimate dream. That is to go home…

- Description from Novelupdates

Xu Jun finally defeated the BOSS–the Dark Demon King, in this stand-alone, virtual reality game. When he wanted to go out to browse Weibo and express his mood, he suddenly encountered a game BUG and immediately passes over to the game world.

He became the man who finally took down the Great Demon King in this world. Gratifying! The attention of millions of people!

……However, he did not know the development of this world was not the same as the game, the Demon King did not die, rather his soul entered into Xu Jun’s body; this Demon King knows of all the stupid things Xu Jun does everyday…….

- Description from Novelupdates