Death March kara Hajimaru Isekai Kyusoukyoku (WN) - Book 3 - 3-5. The Japanese in Different World

He died on the wedding of the girl he had a crush on, after a long and successful career. After convincing Yama to send him back to the world, he decides to fix the areas in which his life went wrong. Realizing the lack of love and romance in his past life, he sets out to conquer the hearts of various women.

- Description from Novelupdates

Embarking on a journey through a mysterious realm filled with boundless dangers and boundless opportunities, Qin Ze, an ordinary soul, is imbued with an extraordinary system that promises unparalleled power and growth. With each challenge overcome, be it fierce battles against demonic beasts or treacherous schemes woven by cunning foes, Qin Ze's strength soars to new heights. This is a tale of relentless progression, where the protagonist's will to survive and thrive fuels his relentless pursuit of becoming the strongest entity in existence. As Qin Ze delves deeper into the secrets of this vast universe, he uncovers ancient legacies, forms powerful alliances, and faces off against the titans that once ruled the land. But amidst the chaos and bloodshed, he never forgets his roots and the promise he made to protect those he cares about. “Unrivaled Ascension” is a thrilling adventure of self-discovery, boundless potential, and the ultimate triumph of perseverance over adversity.

When other people experience a body transformation, it is inevitably either male to female or female to male.

Me? I wake up to find myself transformed into two different bodies.

Both a male body and a female body, one conscience operating two bodies, all sorts of embarrassing moments.

Walking together normally makes other people think that I am sweethearts with my other-self, such sadness.

Also, the entire business of a hero rescuing the beautiful maiden, I call Bull.

I get slashed by a sword and my female body gets abducted, and he wants me to thank him?!?! Can it be less of a tragedy?

- Description from Novelupdates

Facing extinction, humanity seeks salvation in the Astral Verge, a dangerous dimension accessed via portals that threatened to wipe out the entire planet.Few years later, aspiring recruit Daniel Vance enters the Verge for his final assessment, hoping to Awaken a Talent and secure his future. While others gain common abilities, Daniel secretly Awakens the mythical SSS-Grade Talent: [Soul Assimilation]. This allows him to absorb essence, enhancing gear, gaining stats and EXP from slain creatures, and crucially, absorbing attributes and skills from fallen Awakened.Witnessing the swift death of the arrogant Jaxon Rex, Daniel makes a grim choice: he assimilates Jaxon, gaining his first skill, [Kinetic Pulse]. This sets his path: scavenging the aftermath of others’ battles. He enhances gear and, after achieving his first kill on an injured beast, waits patiently to assimilate two more fallen recruits, acquiring [Quick Step] and the invaluable passive [Aura Sense].Starting as average, Daniel rapidly gains power in secret, enhanced gear, multiple skills, and boosted stats , far exceeding his peers while remaining outwardly unremarkable. He navigates the lethal Verge alone, using its inherent dangers to fuel his growth, wrestling with the moral cost of his unique, overwhelming power.