10 nen goshi no HikiNiito o Yamete Gaishutsushitara Jitaku goto Isekai ni Ten'ishiteta - Chapter 3, Part 5 Yuuji’s, Sending Email to His Imouto, Sakura

Xiao Luo and his girlfriend had been in love with each other for four years when she proposed a break up. Because of this, Xiao Luo sped his car in the night and ended up in a car accident. But it was a blessing in disguise as he unexpectedly fused with a high tech system that originated from a universe hundreds of billions of light years away. From this moment on, the entire world started to run amok…..

This is a ‘rebirth’ story where Chen Rong, the heroine, finds her second chance at life after burning herself to death. Set in the Eastern Jin era when bureaucrats and their lofty yet equally hypocritical and oppressive ideas once ruled the empire, Chen Rong is made to use her past life’s experience to survive and hopefully find happiness this time around.

- Description from Novelupdates

A giant golden tortoise, as huge as the world, crosses a broken world.

Seeing the vast world in ruins, Xu Feng slammed the giant golden tortoise on the head.

“Be careful next time, don’t use such brutal methods.”

The story begins with a young turtle-raiser who wants to live a stable life in a small family.

- Description from novelbuddy

Roan, ran away 20 years ago from his rural village in the aim of becoming a Great General. However, all he got 20 years later was just a handful of money and the lowly position of squad commander of the First Legion’s.