Forgotten murim manhua title?

Hello, I've been racking my brain trying to remember what this story is called but I can only remember bits of the synopsis. I would appreciate it if someone can tell me the title if they know it.

At the beginning of the story, the main character goes back to where he is from. We lesnr that the masters he was with (whom he just left) were actually the people who kidnapped him when he was a child. He was experimented on and I think his masters or one of them was referred to as Poison king he endured everything and even made them like him a bit to the point of requesting to go back after years.

Now the bit I'm not sure about (not sure if I'm confusing this story with another) but I think that we see flashbacks of him as a child in which he was taught by these girls to do some sword fighting dance. I think that he later on learns that one of these girls was taken in by a master who is a woman that raises these disciples and then uses them for life force or something. He manages to save that girl along with 2 of her friends....

Let me know if any of this rings a bell