Tree of Aeons - The lab

A mecha otaku is reincarnated into another world as Ernesti Echevalier (Eru). In this world there exist huge humanoid weapons known as Silhouette Knight. Dreaming of piloting those robots, Eru, with childhood friends, Archid Walter and Adeltrud Walter: together they will aim to become a Knight Runner, pilot of Silhoutte Knight.

Zhou Yu, a reclusive otaku, who did not like to go out of his house, was one day forced out of his house by a series of unexpected events.

- Description from Novelupdates

Seventeen-year-old Dominic Hayes had always been a quiet dreamer—chained to hospital beds, IV drips, and the ticking clock of his diagnosis. Leukemia stole his strength, his youth, and finally, his life. But fate had one more surprise waiting for him beyond the veil.When Dominic awakens, it’s not to the afterlife he expected—but to the crashing waves and boundless power of the ocean itself. He has been reborn as Poseidon, the Greek God of the Sea. With divine power surging through his veins and immortality in his grasp, Dominic is no longer the dying boy in the hospital—he is a god.But power comes with purpose.As he grapples with his new identity, ancient forces stir. Old gods rise, long-buried secrets awaken, and the balance between realms begins to crack. Dominic must decide—will he embrace his divine fate and protect the world he once had to leave behind, or will he drown in the very depths of power he never asked for?In this epic journey of rebirth, grief, and second chances, Reincarnated as Poseidon is a tale of what it means to live, to lose, and to rise again with the fury of the tides.side characters :Zeus, Hades and Athena

This is the story of Long Yi, who was killed because he took revenge for the girl he loved. Before he dies, a strange lightning carries his soul into a different realm. How will he live, when the first thing he noticed upon arrival is that, the man whose body he possessed is raping the country’s princess?

- Description from Novelupdates