I am mad cause I had such a good long post that boarded on fanfic for this idea and Tumblr deleted it. I'm re writing it as a fic, but here's a summary of my idea of how Avatar could have been just a little better, just by setting up the Lion Turtle and Energy bending ahead of time.
Imagine Jin was like "yeah that date didn't end the best, but he did kiss me back and he did give me a coupon, that's basically an invitation to come back."
So she does. And she and zuko go on another date and then they're friends/boyfriend-girlfriend, cause its cute damnit!
And then when Zuko and Uncle get to have their shop in the upper ring an move there, they give Jin a job, so she can make some good money for her family, and naturally when they're invited to the palace to serve tea, they bring Jin and then Jin gets caught up in everything and basically ends up in the fight in the underground city with everyone, and this time Zuko's on the avatar's side, cause damn, like, gotta do right by his girl, can't go taking over her home town.
But then, of course, Jin's not a bender, or even a fighter, and aside from the one large rock she manages to smack Azula in the back of the head with cause the princess didn't register her as a threat yet, she's basically a liability, hiding behind Zuko.
Then some how she ends up next to Aang, and he pulls her into his little crystal pyramid with him, and starts meditating.
And then Aang turns into some one else, we wouldn't know it at the time, but this would be Avatar Wan, and he's like "looks like our friends could use some help, wanna give them a hand?"
And Jin really confused, but she's like "I guess?"
And we see Wan put one hand on her forehead and one on her chest and lots of glowing. We don't know what this is yet, but we know it's something.
So then when Aang reappears and finished unlocking that 7th chakra, and they leave the pyramid, we learn Jin can bend now, she like, does it on accident, but like, best of all she's out here Lava bending! Bring lava down over Azula's head!? Bending a river of lava, which the Dia Li can't do anything about cause they're not lavabenders, between them and the avatar. Damn that's cool!
But then Azula still shoots Aang full of lightening, and Katara carries them all away.
I don't really know how well it would go with in the time between then and Aang waking up, but Zuko and Jin are basically accepted as being on their side now. Then they end up traveling with the gaang through the Fire Nation
Here's were some plot set up happens.
Eventually they get a chance to discuss the fact that the avatar can apparently give people bending. Jin explains what he- or the other avatar- did with his hands, and we could have a fun little seen of Aang trying to give Sokka bending powers, but he just cant do it, and Sokkq being disappointed. So he he sits and tries to meditate, and here's were we could have some show-not-tell about the fact Aang can't enter the avatar state with his locked chakra, cause I didn't like how that was so randomly addressed in the show.
So yeah, that could be a running plot along the whole season, of Aang trying to enter the avatar state, or just get in contact with that avatar to learn about this new power and learn how to use it to their advantage.
During the summer solstice, Aang would still meet with Roku, and try to get in contact with Wan, but maybe he's just not connected as strongly with such a long ago past life as he is with his most recent, so it doesn't work, or he only get a minute near the end of the solstice, so he doesn't get much out of Wan.
We could also get Zuko being cute with his girlfriend, cause we all like that, he could be all "I'm so sorry I got you caught up in all this, and Jin would be pretty chill I feel, be all like "nah it's cool, it's kind of tradition for the woman on my family to end up running off with Fire Nation men. Started at the begging of the war when my great-grandmother ran off with a Fire Nation soldier."
Then there could be speculation that she can lavabend (during training sessions with toph she figures out how to regular earthbend) because she has Fire Nation and Earth Kingdom blood, even though lavabending has only ever been an avatar talent (this is also my speculation as to why Bolin was a lavabender in LoK)-and of course, they've always been able to bend all the elements.
We could get some neat training stuff, were she starts bending the lava the was Katara bends water, saying it moves more like water in this state, and Zuko could be all "Uncle says it's important to learn stuff from all four nations" and tells them about lightening redirection, and maybe shows a few fire moves he's come up with based on other bending styles. Katara practice a bit of earthbending style fighting by throwing around some ice chunks like Toph throws boulders. Just a bunch of cross learning from all of them instead of just Aang.
Jin asks katara too if she's able to boil water, cause she, Jin, has tried freezing the earth, but it never gets much cooler than very-warm-but-not-burning, when she changes it back to earth from lava. Katara says she never thought about it and tries. She find out she cant make water warmer, and actually realised that when she changes ice to water, it's freezing, probably only just warm enough to be a liquid at all. They practice until they can change the temperature in both direction, because that's just how I think Bendind should work, you can do pretty much whatever as long as you've got the imagination to think of it, and the persistence to keep trying.
Yeah so the season goes on like that, and with the same general plots as usual. Zuko and Jin join Aang, Toph and Sokka in looking for Ozai on the volcano, Zuko cause he knows his way around, and Jin because, duh, lavabender.
This time they do find the Firelord's chamber in the bunker, but it's empty, probably because they knew Zuko would know where to look.
Things go like canon pretty much till the end, but now we've had some pretty good set up, so when Aang meets the lion turtle, we GET what its showing him, we get that like "oh that's was Wan meant when he said he learn the trick from an old friend!" Or something. Maybe Wan showed a vision of the lion turtle city when he looked nice, so we don't recognize it now with all the ovwe growth, unless we were looking for it, which we totally would be during a second veiwing!
Then during the finale battle when Aang's taking away Ozia's bending it's just like *chefs kiss* a perfect execution of a perfect set up.
And also Jin totally marries Zuko and she's like, actually really great at politics? Damn, that's one fine woman! And all the Fire Nation kids think she's amazing cause they all live on volcanos, you can't tell me Fire Nation kids don't play lavabending, thinking it could be a form of Firebending, like lightening, and like "Look at that guys! The Fire Lady can do it! She can bend Lava!!
Anyway, yeah, that's what I think should have happened.