Ku Y'leh is a very famous old sage who was known for his studies about life beyond death.
It seems that Ku Y'leh was a Necromancer of some kind. His power was such that even his ashes held the capacity to improve life.
Not much is known about him except that when he died, his ashes were preserved in a golden statuette shaped in the form of a bird.
This statue was found many years later in the collection of Meshif, who did not know the contents of the statuette. He traded it to an adventurer when the adventurer brought him a Jade Figurine that helped him complete his Jade collection. The adventurer, on knowing the statue's contents from Deckard Cain, then proceeded to use the ashes to increase his own life, with the help of Alkor the Alchemist.