We never hear any mention of Lu Ten’s mother, implying that I can make any headcanons I want about this, including:
Lu Ten is an Earthbender
That’s it that’s the post goodbye
Ok, but this leads to a series of potential follow-up headcanons:
Lu Ten is commonly believed to be a non-bender
(it’s not widely publicised that the wife of the Crown Prince is from the Earth Kingdom, given the war and everything)
(and then she dies and quickly fades into obscurity)
(besides, no-one looks at a prince of the Fire Nation and thinks ‘hey, I wonder if he’s an earthbender’)
(…this includes Lu Ten himself)
Due to his lack of firebending, Lu Ten becomes proficient with metalweapons instead
(hence why he suggests it as an alternative for Zuko when his cousin is frustrated with his own lack of bending progress)
He knows all the tactical theory - the common attacks and how to counter them, the prefered defences and how to get around them - but he’s never actually seen earthbending
Until he gets to the Front, that is
Lu Ten quickly gains a reputation for being lucky against earthbenders
(he always seems to guess correctly which way to dodge to avoid flying rocks, when to move before the ground erupts from under him)
(there were a couple of notable examples when he was able to warn his unit about imminent ambush by tunnelling earthbenders)
He plays it all off as a combination of luck and perception, but he can’t help but wonder…
He starts paying more attention to the earthbenders he fights, not just matching forms to effects, but the nuances of stance and gesture
Then he goes for a hike one day, far away from anyone who might see, and tries some of the forms for himself
…
…well fuck.
He can’t keep it a secret
Now that he’s finally felt the perfect exhilaration of bending, he’s not sure he can just give it up again
And now that his chi has learned to move in the surrounding earth, he’s not sure he can keep it from reaching out anyway
It only takes one person to see something they shouldn’t, and tell someone they shouldn’t, and he won’t know that the charade has all fallen apart until it’s too late
He can’t tell his father - part of him is worried that Iroh will react badly, but part of him knows he won’t… and that’s worse
(everyone knows that victory in the siege is imminent, the moment that will make the General’s career)
(but the scandal of the Dragon of the West having an earthbender for a son would overshadow even such an achievement)
(he won’t put his father in a position where he has to make that choice)
He can’t tell his grandfather - (Azulon is the Fire Lord, and the good of the Nation will always come first
(while he could overlook Lu Ten being a non-bender, he won’t want to risk of having an earthbender so high in the line of succession)
(not when he has two sons and another two grandchildren all as proper firebenders)
(he’s not sure just what actions his grandfather might take, but he’s not going to wait to find out)
He can’t tell his uncle - Lu Ten has no illusions about the man; he will see this as an opportunity
(while Azulon might be swayed to leniency, Ozai will do everything in his power to permanently remove his nephew… and probably his brother while he’s at it)
(one way or another)
But perhaps that is the answer
Lu Ten is a prince of the Fire Nation. Lu Ten is an earthbender. These facts cannot coexist
He cannot change what he is, but he can change who he is
(it breaks his heart to do this to his father, but it must be done)
Prince Lu Ten dies, and a nameless earthbender slips in through the broken walls of Ba Sing Se
—
(Years later, a golden-eyed earthbender walks into a teashop for a surprise family reunion)
[ID: Two screencaps of Tom from Parks and Rec. In the first, Tom is looking down, and the captions says, “It’s beautiful.” In the second, he is looking at the viewer, and the caption says, “I’ve looked at this for five hours now.” End ID]