The Author Is Speechless - Chapter 22: First Mission.

Liu Duo was a young girl whose grandmother sold her to four brothers with the intent to be a bride. Unwilling, she ran away the following night, only to fall unconscious while trying to get away. Unexpectedly, however, she was reborn with the spirit of a 25 year old woman, also named Liu Duo.

- Description from Novelupdates

Naofumi Iwatani, an uncharismatic Otaku who spends his days on games and manga, suddenly finds himself summoned to a parallel universe! He discovers he is one of four heroes equipped with legendary weapons and tasked with saving the world from its prophesied destruction.

As the Shield Hero, the weakest of the heroes, all is not as it seems. Naofumi is soon alone, penniless, and betrayed. With no one to turn to, and nowhere to run, he is left with only his shield. Now, Naofumi must rise to become the legendary Shield Hero and save the world!

He was sent to a world where different races and beings wage different types of wars and fight for supremacy.With a body of a mere mortal, he learned the way of the immortal craft and a different cultivation technique. Making him able to roam the land searching for a place where he could belong.How can he survive in this dog-eat-dog world he knows not. But combining the ingenious designs of the modern world and immortal energy, otherworldly devastation awaits those who face, the geared immortal.