Okay folks. This is my second story so I thought I'd try something different. This is a crossover of my two favorite shows. Disclaimer: Avengers: Earth's Mightiest Heroes belongs to Marvel as do all its characters, locations, and terms. Legend of Korra belongs to Nickelodeon as do all its characters, locations, and terms. Now just sit back, relax, and enjoy.
Prologue: I am the Watcher.
So vastly complicated and yet wonderfully simple.
It is home to over a billion galaxies; stretching out into infinity and racing toward its inevitable end. It is host life forms so diversified that no one race could have ever imagined the others. Time and time again these races have met. Some like the thinkers of Zenn-La seek peace and enlightenment. Others like the Kree and the Skrulls seek to conquer and subjugate all others. And still others seek only death.
It is in this one sector of the universe, a galaxy known as the Milky Way, that two sister planets reside. Like antipodes they exist at opposite points of the galaxy. On one side we have the planet Earth, although primitive by most standards, its technology has led to the rise of threats beyond the imagination of most life forms. To combat these threats certain individuals with unique skills and abilities taken it upon themselves to serve as this worlds protectors. For you see, this is the world of Heroes.
On the other side we have a world which has no name. It is a world where ancient tradition melds with modern technology. This is the world of the Benders. This young world has no unique elements or strategic value so it is beneath the notice of most advanced races. In its entire history it has never been invaded or in fact had any contact with any race from beyond its atmosphere.
However that is about to change. For you see dear friend, today this world will lose its innocence. Today this nameless world will be visited by a being from beyond. A being with powers beyond their scope of understanding. He is the titan Thanos, Servant of Death, and his arrival will spell destruction for the people of this world. And although it breaks my heart, I can do nothing to stop this impending tragedy.
For you see, I am Uatu the Watcher. I am charged with recording all events of significance in this sector of the cosmos. It is a task that brings me great joy and great sorrow.
End Notes: BTW I based a good chunk of the dialogue in this off the first episode of Silver Surfer the animated series which is also owned by Marvel. So tell me what you think.