MTL - Little Mermaid Dressed As a Scientist - Chapter 57

Ding!『You have acquired the skill: [Universal Language] – All tongues shall now bend to your understanding.』『You have acquired the skill: [Dimensional Exchange] 』『Item Detected: [Gold Coin x50] 』Initiating Currency Exchange…Exchange Rate: 1 Gold Coin = $1,000 USDConverting [50 Gold Coins] → [$50,000 USD].....Kael Lancaster grew up believing his family was ordinary—until he discovered that his estranged grandfather, Theodore, was a multi billionaire.Struggling with his family's debts and uncertain future, Kael decides to approach his grandfather and move into the Lancaster estate, becoming the old man's caretaker. For two years, he endures the family's contempt and Theodore's cold indifference, clinging to the hope that his loyalty will one day be rewarded.But when Theodore dies, the will delivers a brutal blow: Kael inherits nothing.Or so it seems.However, His grandfather had left him something else.A portal through which he could travel to another world—Kael can trade between worlds, amassing power beyond imagination.

When an S-class elite assassin-raised captain of a special ops suicide squad comes home from a high-stakes Africa mission, he finds himself offered something that could potentially set him up for life- a curious assignment that he could use to finally exit his days of war and slaughter.

He is the ruler of the mercenary realm, an overlord that gives headaches to the leaders of any country! For the sake of his friends, he’s willing to sacrifice himself; for the sake of his family, he does not hesitate to spill blood! He is a dragon, one that soars above even the highest of heavens. He’s a power that advances triumphantly through unstable situations, stirring up both the winds and the waters.

- Description from Novelupdates

“I'll take this child.” Sold to the Wudang Sect's outer martial arts training hall for three silver coins at a young age, Kwak Yeon dreams of mastering supreme martial arts. But can he overcome the needle-sized gateway barely permitted to trainee instructors and rise to become a disciple of the main sect? “A true gentleman cannot stand idle in the face of injustice!” Thus begins Kwak Yeon's unyielding journey through the martial world, following the ruthless principle of “Kill Buddha, Kill Ancestors”—destroying all obstacles in his path!