I'm ripping this off of 453's Avatar story (here and here). It's unofficial (since she prefers a happy ending), and it probably won't be very funny (beyond poking mild fun at Selax's being overly prepared); however, (almost) every story could use an unhappy ending at some point or other
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(I'm also counting this an entry to the Fall chron challenge even though it will reference only a few parts I got off the wiki for the show.)
*BiC*
Beorn watched everyone else walk away. Even the dejected airbenders finally left, convinced their master was dead.
No one had even said "thank you."
Kids these days, he thought. No wonder he had to make their lives miserable. They were practically asking for it!
When the others were long gone, Beorn placed his hands over the spot where Selax had died.
Nothing happened.
He frowned and tried again.
Still nothing happened.
Then, he muttered, "Oh, that's right."
He waved his hands in some vague manner that apparently let people control the elements.
The area began to glow, and Beorn's image began to ripple and distort.
A moment later "Beorn" was gone and Selax stood in his place.
There, the elemental thought to himself. Another seventy years and I should have all the bugs out of this "Dark Avatar" process.
He frowned internally.
Or was it ten thousand years?
Oh, well. He had time.
Releasing the Avatar spirit to Tiernan had not been intended to torment the prince--well, maybe it had...but only 99% for that reason (and the firebender deserved it for his poor manners)--but to enable the elemental to start his own reincarnation cycle (on the off chance someone actually killed him...one could never be too prepared after all).
Admittedly, his first effort had gone a little wrong. He hadn't been supposed to reincarnate as the powerless Beorn, let alone before he actually died at all. (Selax was still trying to figure out how that had happened.) It had made it unfortunately necessary for him to help kill his other self and get the cycle working properly.
It should also leave him free to torment Avatara with the convenient alibi of being too dead to do so, but that wouldn't stop Avatara from suspecting him. Until he fixed the "Dark Avatar" process, he'd have to be discreet and mostly leave that task to zombie-Rythan.
Rythan didn't think anyone knew that he had--years ago--set up a process to zombiefy himself upon his first death, but Selax had, of course, anticipated that action and prepared a contingency plan for it (long before Rythan was actually born...one never could be too prepared). He had also calculated that zombie-Rythan would resurrect Iannah as zombie-Iannah, who would then ruin Scry's life and turn her against Avatara. According to the plans he'd made a few millennia ago, Scry would then ruin Katerei's life and turn her against Avatara.
Actually, if all went as expected, pretty much the whole world would turn against Avatara. Firecat would eventually drive the man insane with hallucinations of Airedain.
It was all a sadly necessary part of Selax's ongoing plan--often mistaken for attempting to take over the world--to make the lives of everyone in the present miserable so that people in the future could be happy.
Of course, future generations had a habit of becoming the present generation at some point, so no one had actually yet gotten to enjoy the results of his work. That was a problem he was still trying to solve...he was certain he'd figure it out eventually (probably).
On the note of helping future generations, he wondered if he should let someone know that Adrianna had indeed died at the North Pole and that the current Adrianna was actually from a mirror-universe and was the first scout of an invading army.
The elemental considered whether or not he ought to stop her.
Of course, she was tasked with making Avatara's life miserable during her mission...
Selax shrugged. That was worth the invasion. He'd deal with it later.
With that thought, the elemental vanished into the shadows of the gathering night.