After Rebirth, I Married the Great Demon King - Chapter 6 So Obedient

Yang Feng somehow transmigrated into a different world and received a legacy of an ‘ancient high tech’ family, which does not directly raise his power, but gives him the technology to build things which are way more advanced than the seemingly medieval world.

But to build something you need resources and energy. To receive resources you need strength. To gain strength you need knowledge. To gain knowledge you… need strength? or a background? Or maybe a fully armed army of high tech robots who aren’t afraid of death?

But is this legacy really for him to keep?

- Description from Novelupdates

Sumi has always despised the world she lives in—one filled with greed, deceit, and pain. Trapped in a miserable life with a dead-end job and mounting debt, she sees no escape. But when her lecherous boss crosses the line, Sumi reaches her breaking point. In a desperate act, she takes her own life—only to awaken in the darkness and found out that her wish has been granted she is no longer human she finds herself in the most unexpected form… a seed of a flower and she was in the world which she only knows in game and stories. a world where creature like demon, monster and things like magic and spells exist and she is going to live her second life… as a flower.

Forcefully brought over from the modern world to an alternate world, Wang Chong felt detached and lived his life aimlessly.

However, when calamity struck and he saw his family and everything he cared for being torn apart, he felt regret.

Thus, he stood up and eventually became the Grand Marshal of the Central Plains, leading an army against those who seek to destroy all he cherished.

Yet, despite all his efforts, it was already too late to reverse destiny.

But before his death, a shooting star, the same one which brought him to this world, appeared before him, and he was given another chance to undo his regrets.

This is a cliché story about two young people saving the world.