Naruto System in One Piece - Chapter 9: Sea King

The Main Character, Watari Karito, is a veteran player of a Military Shooting VRMMORPG.

Upon awakening, Su Changkong found himself transmigrated to a world thrown into chaos by war and rampaged by demon monsters, where his martial arts talent was mediocre. However, Su Changkong discovered that as long as his own “life span” increased, his talents and potential could also be “limitlessly” enhanced!Cultivating the Health-preserving Fist technique and practicing the qi of longevity! The path to immortality is littered with corpses, and Su Changkong embarked on a Martial Arts path where he would not perish, even if heaven and earth were to be annihilated!

Being given a chance and reincarnated is nice and all, yet why do I have to become that male friend who just watches the protagonist flirting with his harem?---World: Kaguya-sama: Love Is War - Hyouka ----