I have to start off by saying, of course this story/stories will take place outside of the established avatar canon. So in no way shape or form would this interfere and/or influence the main avatar storyline/timeline. So please as you're reading this article; do not worry if I take any liberties or even choose to kill off a couple characters here and there. This is purely fan fiction. Lastly I also want to make some points very clear. In all of these stories the zombies would retain their bending abilities. But of course these undead benders be significantly more violent, more ruthless, and way more durable. I will also be using the word "zombie" very freely, you'll see.
Immortality in the avatar world
Spoiler alert for those who have yet to read the Kyoshi comics. Yes the topic of immortality has already been addressed in the Kyoshi comics. Basically there has only been one person by the name of "Lao Ge" who has ever been "immortal". However that was not true immortality but just extremely prolonged life, sure in theory you prolong indefinitely which would mean immortality but no one has ever been truly immortal. Also even the theory of extracting the chi of an avatar was just a theory. I felt the need to mention this because it's important to the existing lore, but every time I tried to spin this to zombies just became stupid. So I will NOT be talking about this for my theories.
Now there are a few ways I could see zombies being introduced into the Avatar world. Let's take a look.
Swamp benders creating zombies?
You read that right. I'd introduce probably one of the most insane benders in history. I was inspired by both Magneto in "Days of Future Past" when he lines the insides of the sentinels with metal so he can control them. Also I was inspired by the scene when Nathan from "Misfits" was paralyzed by Brian (aka "Monsieur Grand Fromage"), when Brian wraps the mozzarella around Nathan's central cortex.
So I got to thinking, we got to see how helpless a person can be when they're at the hands of a blood bender, however that takes an immensely powerful blood bender and their complete concentration. With our swap bender (he/she), is able to intertwine vines throughout the central nervous system. And by manipulating the vines, these benders become puppets. However the reason why they're "zombies", and I'm using that word very freely. Their completely at the will of this antagonist in a vegetative state. Aware of all that is going around but even more helpless then when you're under control of a blood bender.
This is the scene from "Days of Future Past" for reference.
Avatar Legacy Virus?
For those of you unfamiliar with the legacy virus from the X-Men. In the future, Apocalypse created a virus to destroy humanity. However, through a series of events, the disease evolved and actually ended up attacking mutants x genes, thus killing various mutants as they tried to use their powers. So, borrowing from that we have another non-bender vs bender conflict. These events take place in a very modernized version of the avatar world, so learning from the failures of Amon instead of just temporarily disabling a bender's powers. This avid anti bender and geneticist has created a virus not only to stop someone's bending permanently but also kill them. However due to a series of unforeseen and unaccounted for events, this virus reanimates the dead after they've been infected. Thus creating zombies.
Oh look, I'm just flat out stealing again. But I mean, hey. Why not? In a future avatar world, the T virus is created for the exact same reason it was in the Resident Evil films, and events play out basically the same way they did. Except with telekinesis and clones, just give them bending. It's really that simple. Once again, why not?
So this was actually a very late addition, but I think it would be a great. Now yes, I'm just stealing the premise of iZombie and throwing in bending, I don't care. That show was amazing, and yes this means I lied about brutal, ruthless, and mindless zombies. But once again this is my article and I'm going to write what ever I want. Anyways, I think this premise would be the most logical as to how a bender could retain their bending despite being a zombie. Also just imagining rage mode with bending, now that would be a sight to see.
Thank you for your time, I hope you enjoyed what you read today. I have plenty of different articles on many different topics. Feel free to give those other articles a read or two. Also if you'd be so kind, I'd greatly appreciate a heart and if you really feel so inclined tips are always appreciated but by no means required.