The Yin-Yang Ghost Slayer

[No System + nearly invincible + gradual growth + urban fantasy + supernatural + companions]

I was born on the Dragon Boat Festival, the day with the strongest yang energy, at the hour of the Horse, when yang energy is at its peak. But by a coincidence, I was also born inside a coffin meant for the dead, leaving me naturally possessing both yin and yang. My grandfather found me and took me in as his disciple, teaching me martial arts.

My grandfather also passed down two blades to me, one yin and one yang. The yang blade slays ghosts, while the yin blade guides them onward. From then on, the martial world had a new ghost slayer.