Cthulhu Gonfalon - Chapter 19

Crying blood and tears, she pledged a poisonous vow. The gods did not fail her. She was sent back to a decade ago. The legitimate daughter of Jiang family returned from hell.

The story is about a boy entering high school, who answers a strange call from a public phone one night. The caller challenges him to a bet: She’ll remove the birthmark which he sees as the cause of so many problems, and he’ll have fifty days to win the heart of a girl he’d considered far beyond his reach. And with this, a very strange summer begins.

When Jiang Cheng was told to return to a family that he never knew or had a relationship with, he had never expected to end up meeting a young girl, and eventually, her seemingly roguish brother Gu Fei, as a first encounter in the new city.

In the era of universal mechas, people can go to the endless abyss, collect materials, strengthen and forge their own mechas, and master the power of destroying the world.

Jiang Chen traveled through time and awakened his talent [Immortal Unarmed]. Once the mecha is broken, he can permanently absorb its power and receive multiple bonuses.

…

At the bottom of the abyss, when the Old Demon God finally broke the Titan mecha with great effort, a hand stretched out from the fragments and held down its head.

“Congratulations, you have unlocked my limiter.”

- Description from novelbuddy