Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Volume 18 Chapter 16. Satou’s General Store [3]

He Lang died by his own hands for the sake of his imperial younger brother’s ambition, whom he loved. He was offered to be reborn in exchange for giving up his past romantic feelings. Reborn without the burden of his romantic feelings, he brings with him a manual to new worlds. He wholeheartedly followed the instructions of the manual to complete the tasks, not knowing that the originally slag gong was blackening…
He pleaded to his affectionate Emperor brother to release him, he pleaded to the paranoid prisoner next door, but until the end he remained baffled.
In the end, he discovered that the full name of the manual was – “Slag Shou Cultivating Manual”
Σ (っ ° ° °;) っ!

- Description from Novelupdates

You had taken up the Student profession

You had now reached level 7.

Acquired skills: elementary school knowledge, junior school knowledge, and senior high school knowledge.

You took the university entrance exam and scored full marks.

Your have been upgraded to level 9, and you have activated the profession-change interface.

You became a scientist and gained R&D skills.

You used R&D skills and gained space fortress-building technology.

You used R&D skills and gained starship technology.

You are now invincible.

Li Yuanqing transmigrated and became the crown prince of Northern Kingdom. He was sent to the borders, after his cultivation and meridans was crippled, because he refused to marry a princess and was not allowed back into the palace ever.

Just then, the Hundred-fold Sign-in System was activated!

Outside his house in the Wilderness, he signed in and received 100 Replenishment pills!

Beside the lake of the Wilderness, he signed in and received 100 Marrow Cleansing pills!

Among the warriors of Myriad City Kingdom, he signed in and received 100 Heavenly Skill manuals!

…

Li Yuanqing had thought that if he just signed in silently and received the hundred-fold reward, he would be able to watch over his younger sister until she became the ruler of the kingdom and until he became invincible.

But he had never thought that one day, the queen of Myriad City Kingdom would come to meet him!

“I am willing to use Myriad City as my dowry. Will you marry me, Your Highness?”

Li Yuanqing did not know what to do when he looked at the queen smiling beautifully before him…

Short, rich, and handsome, Lin Feiran was always the center of attention. But after transferring schools in his second year of high school, he discovered that his limelight was snatched by his Adonis classmate, Gu Kaifeng.