MTL - Old Enemy Became Sweet and Sticky - Chapter 17

King Grey has unrivaled strength, wealth, and prestige in a world governed by martial ability. However, solitude lingers closely behind those with great power. Beneath the glamorous exterior of a powerful king lurks the shell of man, devoid of purpose and will. 

Reincarnated into a new world filled with magic and monsters, the king has a second chance to relive his life. Correcting the mistakes of his past will not be his only challenge, however. Underneath the peace and prosperity of the new world is an undercurrent threatening to destroy everything he has worked for, questioning his role and reason for being born again. 

This is a world with only oceans, through which scattered are countless small islands and treasures.With swords, gunpowder, sailing ships, and most important, the Treasure Hunting System, Alka is ready to dominate the oceans!「Map detected」「Scanning for Treasure」「Scan complete」「Happy Treasure hunting!」

Li Xu occasionally got a sign-in system, and his life has been different from now on. Enjoy life, look at the scenery, sign in, spring flowers bloom, and face the sea.

- Description from novelbuddy

Always looked down upon by others, Ji Feng gains technology far more advanced than the present, as he discovers its abilities, he begins to walk a path far from ordinary. With X-ray vision allowing his to find jade stones in rocks. With this futuristic technology, Ji Feng accomplishes something no-one can compare to. This is the beginning of a legend.

- Description from Novelupdates