Ok, but this leads to a series of potential follow-up headcanons:
Lu Ten is commonly believed to be a non-bender
(his father might be the Dragon of the West, but his mother was a non-bender - from one of the newer colonies, wasnât she?)
(their son must take after her side of the family)
(besides, no-one looks at a prince of the Fire Nation and thinks âhey, I wonder if heâs an earthbenderâ)
(âŠthis 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 preferred defences and how to get around them - but heâs 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 canât help but wonderâŠ
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
He canât keep it a secret
Now that heâs finally felt the perfect exhilaration of bending, heâs not sure he can just give it up again
And now that his chi has learned to move in the surrounding earth, heâs not sure he can keep it from reaching out anyway
It only takes one person to see something they shouldnât, and tell someone they shouldnât, and he wonât know that the charade has all fallen apart until itâs too late
He canât tell his father - part of him is worried that Iroh will react badly, but part of him knows he wonât⊠and thatâs worse
(everyone knows that victory in the siege is imminent, the moment that will make the Generalâs career)
(but the scandal of the Dragon of the West having an earthbender for a son would overshadow even such an achievement)
(he wonât put his father in a position where he has to make that choice)
He canât 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 wonât 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)
(heâs not sure just what actions his grandfather might take, but heâs not going to wait to find out)
He canât tell his uncle -Â 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 heâs at it)
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)