Wukong:
Wukong is directly inspired by the main character of A Journey to the West, Sun Wukong (transcription in Chinese, or Son Goku in Japanese). It's a traditionnal Chinese novel.
He's a monkey born from a similar magical stone (<=> runic stone, and his passive too!), very strong and clever, so he was entitled Monkey King by the other monkeys.
He eventually became a student of a taoist master (<=> Master Yi, wuju master) and got thename Sun Wukong, meaning monkey aware of emptiness.
Under that study he was taught 72 transformations and other things, like transforming his hairs into objects or clones (<=> Decoy), or cloud travelling (<=> Nimbus Strike).
After that Sun Wukong was very powerful and beat the guardians of the Eastern Seas (<=> Chinese artwork) to get his equipment, especially a magical staff which can change its size depending on Sun Wukong's will. (<=> his weapon, his classic skin)
He brought lots of problems in the living world, so the Jade Emporor, leader of the Heavenly Kingdom, gave him a job (which will happen to be the lowest job in heaven), hence one of his skin. And let's say Sun Wukong is not quite happy about that. =p
The story of Sun Wukong is far from over but i don't see anything left related with the champion in LoL. You can check the entire story if you want, the story is very reputed in Eastern Asia!