Moto Sekai Ichi'i no Sub-chara Ikusei Nikki - Chapter 65: Audience, Decision

A young boy genius, Suo Jia, is a water mage who dreams of being a warrior travelling the great and dangerous trade routes to find his lost father that set off on them before Suo Jia was born. Having to look after his sick mother, Suo Jia manages to find a way to solve all their problems, as well as make a name for himself. He gathers nobility, vast wealth, items of great power, knowledge lost to the ages, and exceptionally talented females around him as he plots and plans – preparing to set off on an epic journey that will go down in history as a new legend. However, will others that depend on his powers so much be willing to let him go on such a dangerous journey so easily?

- Description from Novelupdates

Roy died during a war against the Evil God Cult, but somehow, he returned back in time to 30 years in the past where he was just a boy who awaken his summoning magic.

When a person dies, they either die light as a feather (aka unimportant) or heavy as Mt. Tai (aka very important).

The chief female forensic investigator, Ran Yan was secretly killed by her assistant. Unexpectedly, she was reborn in the years of the Tang dynasty. After experiencing a narrow escape, she fled from Jiangnan to Chang’an. Although, Chang’an was at the beginning of its flourishing period under the Li family’s Tang dynasty, various princes were vying for the throne by using all kinds of strategies. This was the dark days of the imperial court, where one needed to walk on a tightrope as one’s life was as powerless as an ant. The Xiao family controlled a large amount of wealth so inevitably they also became involved in the conflicts.

After arriving in Chang’an, she discovered many suspicious incidents: the original owner had unexplainable amnesia but his family was indifferent. She once again saw the orchid shaped clay inkstone, a valuable object that her mother has given her in modern times. Hence, could it be that she can time travel back? In order to survive in the Tang dynasty, she displayed her strong spirit and willpower by learning medicine from a doctor, pretended that she benefited from being sick on how to cure diseases, suffered hardship in earning money, manufactured penicillin, cured syphilis, and used her autopsy skill and experience to solve each and every murder mysteries.

- Description from Novelupdates