Meet Wendell Rand, Daniel's Father.
He first discovered the city of K'un L'un as a young boy and while he was chilling there he thought "I'm gonna save Lord Tuan" , the city ruler, and so he did.
Lord Tuan then figured "I'm gonna adopt him" and so he did.
Wendell chilled again for a while then decided, "I'm going back to america and make the next Iron Fist, we cool Tuan?" Tuan said "We cool.", and so he did, while he was at it he also built a million dollar company, for giggles obviously.
(Disclaimer: factually what happened but not HOW it really happened.)
Anyway, he married, had a little boy named Daniel (DUH!) and when Daniel was old enough he organized an expedition to find K'un L'un again just this time... He didn't.
Tune in next time to find out what happened.
In the mean time, make good art.