Isekai Saikou no Kizoku, Harem wo Fuyasu Hodo Tsuyoku Naru

A man named Yuuto is reborn into a fantasy world through a smartphone game as the third son of a noble family. In this world, individuals possess "Skills," and Yuuto is born with the "Noblesse oblige" ability. As an adult, when he embraces a woman during a formal ceremony, this skill activates, allowing him to copy her abilities. He repeatedly embraces women with powerful Skills, gaining their powers and forming a group of women who develop feelings for him. It is later revealed that "Noblesse oblige" can also awaken and enhance Skills. Yuuto continues to acquire abilities through these interactions, growing stronger and accumulating a harem.