My SSS-Rank Grim Reaper System - Chapter 1: The Day of Summoning

At 18, Alex Kain is whisked away to Eryndor, a game-like realm where he gains 'Skill Synthesis', a talent to fuse skills into godlike powers. Battling monsters and conquering dungeons, he builds a harem of strong women drawn to his might and charm. With the power to return to Earth bearing incredible resources, Alex faces a growing threat that endangers both worlds in this epic of adventure, romance, and ambition.

The empire has turned into the land of the undead due to a spell gone wrong. God summoned heroes from countless worlds to purify the empire and plant new hope. Lee Shin Woo, an ordinary earthling, was also summoned. As an undead, that is.

With divine medical skills in his left hand and supreme martial arts in his right, carrying a century of memories, he was reborn and returned to the city. This life, he vowed to dominate everything, take control of all, and ascend to the zenith of the heavens!