All info comes from the wikipedia, of course.
The most famous alchemist of the far East is Elder Zhang Guo. In fact, he's known as one of the Eight Immortals which are held as deities. He lived during the Tang Dynasty and worked as an alchemist under Empress Wu. He was pretty eccentric (read: completely weird/crazy @_@)-- he rode his white donkey backwards, and he always carried around a phoenix feather or a peach, two symbols for immortality (oriental alchemists were more focused on the spiritual products of alchemy, i.e.: immortality, than the occidental alchemists, who were looking mostly for material products like turning lead into gold and such, though there are exceptions, of course). Zhang Guo also declared that in a past life he had served as Prime Minister to Emperor Yao, who was one of the most revered semi-mythical Chinese Emperors and most likely the source of Ling's family name.
As a funny detail, Zhang Guo also has a kung-fu style dedicated to him (I figured it might have something to do with the fact that Ling can fight?), and it is a pretty funky, unconventional style of fighting.