Yet again, I have a theory...
Most people have probably considered that the Earth King will be a new man, but I think it's an aforementioned character, I think it's Iroh's one and only son, Lu Ten. I may be wrong. This is pure speculation. The following screenshots are courtesy of AvatarSpirit.Net.
The Earth King:
Lu Ten:
As you can see, they look similar. Even though Lu Ten is a painting, it resembles the Earth King's shadowed face. The only difference is the chin. Lu Ten has a flat chin, while the Earth King's is pointed. Plus, Lu Ten's face is more square, while the Earth King's is vertically elongated. The factors that variate our thinking are: animation style, real versus painted-on-paper, zoom, and position. So there remains a slight possibility that they are the same person.
Okay, you are all probably thinking I'm crazy because as we all think, Lu Ten is dead. But no one really has clearly specified his death. Iroh always mentions that he lost his son, not necessarily that he died. In Zuko Alone, when Ursa receives mail from the war front confirming that "Lu Ten did not survive the battle." This doesn't mean that Lu Ten died during battle, maybe it means he escaped the battle before it ended, perhaps captured by the Dai Li. Did you notice that Iroh knew where Lake Laogai was and, most importantly, that there were prison cells under it? He may have come as far as Lake Laogai during his 600-day siege, unfortunately for the Fire Nation, being expunged before reaching the Inner wall of Ba Sing Se. Maybe there is a complex story of what may have happened with Iroh and Lu Ten under Lake Laogai. For example, the Dai Li may have executeed Lu Ten while brainwashed Iroh watched.
Think about how complicated the story plot would become, and for Iroh to find out, its a heck of alot to take in. Lets hope we find out in Book 2-Chapter 18-The Earth King. But why would the Ba Sing Se government, mainly Long Feng, want a Fire Nation prince [Lu Ten] to be their Earth King? Perhaps Lu Ten was against the war. Perhaps Lu Ten was brainwashed during all these years. Maybe there is a well thought out plan by Long Feng for throning Lu Ten, Long Feng could not betray a fellow Earth Kingdom citizen and appointed a brainwashed man from the Fire Nation putting the Fire Nation at an akward position during their interaction with Ba Sing Se. Something along those lines, its complicated to think this through.
Try it, what do you think? How would Iroh respond if his son Lu Ten weren't really dead, but the Earth King of Ba Sing Se(if he was)? How would Zuko and the Aang gang? How would Ba Sing Se? How would the world?
I'll continue to update the theory, especially after what we could come across in Book 2-Chapter 18-The Earth King. Post your thoughts here. Thanks!
*Remember this is pure speculation
Edited 2 total times.