My Dao Companion Is Actually the Sword Venerable of the Immortal Realm

Genius, Invincible, Cold-Blooded, and Ruthless; Profit Above All. No System, No Romance

I want traditional fantasy where the protagonist isn't a good-for-nothing from the start, but is invincible, cold-blooded, ruthless, and puts self-interest first. Let me say it again: traditional fantasy only. Don't recommend anything else. The protagonist should be decisive and merciless, not a bleeding heart or a simp. Please recommend something if you know any, and it needs to be long. No abandoned stories or dumbed-down novels.