MTL - Guardian - Chapter 53 Merit pen

Lucas Yohan, originally born in a world filled with magic and mana, gets transmigrated for the second time into an advanced interstellar world that blends strange magic and technology in ways he never thought could be possible. Upon awakening, he discovers that his transmigrations were no coincidences and is now in possession of the Crafts-God System, a system dedicated to creating a new successor to the deceased Crafts-God, who is an existence with the ability to create anything and everything. Lucas decides to fulfill the goal of the system and become the new Crafts-God, but he’s faced with an incredulous challenge; he can’t learn magic.

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

After the nuclear warfare, massacres started to spread throughout the entire world. The order between humans completely collapses, and the strong eats while the weak gets eaten becomes the #1 rule.

The first time they met they had battled fiercely, just for a mere bunch of herbs. She needed it to save people, and he wanted to use it to save his own life.