The Nine-Turn Yin-Yang Pill was a peerless immortal pill on par with the Bone-Forging Pill of Genesis.
Such an item was truly impossible to find out in the outside world, yet Hogwarts University actually had a finished one in its possession.
It was said to have been plundered from China during the old era by a certain foreign nation, and the headmaster had later bought it back to keep in the school's treasury.
Chapter 469