MTL - Star Rank Hunter - Chapter 376 "water" bomb

After the brutal loss of his beloved grandfather, Liam Hunter embarks on a harrowing journey into the heart of the Dark Forest, known as the Forest of Kyrell, with a singular goal: to gain the strength necessary to honor his grandfather’s memory and to never lose anyone dear to him again. At just ten years old, Liam is thrust into a world of darkness and malevolence, where he endures four grueling years of training and transformation. In this shadowy realm, he is reborn as a fierce warrior, driven by a relentless desire to eradicate every demon and ultimately confront the Demon King, Emrys himself. To achieve his formidable goal, Liam must forsake any emotional connections that could weaken his resolve. The once vibrant and joyful boy is transformed by his trials into a cold and unfeeling combatant, hardened by the harsh realities of his quest. This is the story of Liam Hunter—the last wielder of dark magic—whose journey through darkness and sacrifice will shape him into a force of vengeance and resolve.

This legend tells the tale of the protagonist, Kuroki summoned to protect the demon king from the hero.

Kuroki, unbeknownst to him, suddenly came to another world. He was summoned by the demon king, Modes. The territory which the demon king overrules was in the midst of being destroyed because of the hero. He had no choice but to bow before Kuroki.

“Please save us, Savior Dono!”

Kuroki nodded, deciding to save the demon king due to an unexpected turn of event.

After breaking up with his girlfriend, he accidentally acquired a genius system and rose from there against the heavens, becoming invincible..

- Description from Novelupdates

After his qi center is destroyed, a martial arts instructor of the Blood Demon Cult is assigned to learn and research the martial arts of four captured murim masters. However, when the Cult betrays him and decides to kill him, he fights back and everyone in the Cult dies, including himself.He then mysteriously wakes up in the body of Baek Suryong, a young martial arts instructor in the rural countryside with a disease that will kill him within three years. He realizes that the martial arts he had learned holds the key to healing his new body’s illness, but in order to do that, he needed money. A LOT of money.Baek Suryong thus embarks on a journey to become the Star Instructor of the Azure Dragon Martial Arts Academy, and earn enough money to save his own life! Perhaps he would even manage to educate some kids along the way…