I'll make you the furnace and the cauldron, so you can refine Yin and Yang and prove the Great

He transmigrated into the body of a hundred-year-old man and was captured by the Hehuan Sect to be used as a furnace cauldron.
Li Hanshan was speechless: "I'm so old I'm practically falling apart, and you guys are still so picky about food!"
When the witches saw him, their eyes turned green with envy—
"He's lived to be a hundred and his virginity hasn't depleted?! This old treasure, I'll take him for ten thousand spirit stones!"
The most alluring inner sect prodigy, Hua Nongying, stole him away. Her clothes slipped under the bed curtains, and her eyes flashed with seductive allure.
"Come, let this fairy taste how sweet your old tree blossoms are~"
A night of turmoil.
Hua Nongying, clutching her aching back, her legs trembling, cried out, "You... just who are you?!"
Li Hanshan slowly fastened his belt, then turned back and chuckled.
"Call me master."
She used him as a furnace, and he drained her into becoming his slave.
The whole clan was waiting to see him drained dry, but as they waited and waited—
How come this old man is getting more and more energetic as he gets older, and his cultivation level is increasing by leaps and bounds?!
The demonesses panicked: "Run! This old man is even more ruthless than us!"