Lei Kung, The Thunderer
First appearance: Marvel Premiere 18.
Powers: Apart from being immortal, none. Lei Kung is, however, an excellent teacher and a formidable martial artist who once single-handedly saved the legendary city of K'un L'un from being captured by the dimension-spanning Ninja.
History: Chief warrior of K'un L'un, Lei Kung spent eons training young men to defeat the dragon Shou Loa and obtain the Iron Fist. And for eons, young men failed -- even Lei Kung's own son Davos, who became the embittered super-villain Steel Serpent. Then new blood came to K'un L'un in the person of half-breed Danny Rand-Kai. From almost the first day of his training, Lei Kung realized Danny could, indeed, be the one to successfully challenge the dragon, and lavished all his time and attention on the youngster. When Danny became the Iron Fist, everything in K'un L'un changed. Master Khan, angered at the death of his dragon, demanded Iron Fist as a blood sacrifice. Lei Kung's intervention saved Danny's life. After Danny was imprisoned by the H'ylthri, Lei Kung was among those who helped free him. When Davos stole the Iron Fist and returned to K'un L'un, the Thunderer brought Danny into the city to defeat the Steel Serpent, knowing that only the true Iron Fist could prevent his son from becoming a tyrant.
Current status: The man Danny Rand once called "father" remains in K'un L'un, training the next generation of immortals and hoping against hope Davos will reform and return.
