MTL - Knight’s Love Letter - Chapter 2

Yggdrasil, the World Tree of Norse Mythology, suddenly appeared on Earth. And with it came demonic creatures that ravaged entire cities.Although not all hope is lost, due to the System that a few special humans had gained.In this new world where only the strong survived, Min JaeHyun scrapes by regretting the wrong choices he’d made in the past… when one day, he gains the only Mythic item in the world.How will this item help him? And can he change his wretched fate?

To treat her sick brother, she was forced to marry him in place of her cousin, who was disfigured and paralyzed. At first, their relationship was purely transactional, with neither caring much for the other. But after going through a lot together, they fell in love with each other. He doted on her deeply.She was considered an ordinary person by the world, but it was later discovered that she had multiple identities - a mysterious underground boxing champion, a highly-skilled doctor, and a mysterious and renowned composer... He also realized that their fates had been intertwined long before they met.

I finally managed to kill the demon lord.