Second chapter
Zuko and Iroh were running to the closest ship, but this was the center of the royal city so the closest ones were three kilometers away.
"Uncle!"
"Yes Zuko?"
"I'll need your help, right now my chi reserves are not deep enough so I can't fight for much time."
"With a shallow chi reserves you managed to use that surprising technique?!"
"Not really, I used the energy from the thunder and the fire my father used, but right now my power is not enough to use thunderfire at that level"
"I'll need an explanation Zuko!"
"I know… be careful!"
Some royal guards near the entrance used their firebending to completely block the entrance, but Iroh even with his calm demeanor is a hardened veteran so he forcibly broke the "fire wall" and the remanants were used by Zuko to restore himself a little.
This scene repeated many times in the city, Iroh used raw strength to forcibly disperse fire attacks allowing Zuko to absorb more and more energy but many times Zuko was also forced to take action they were outnumbered 1000:1 so this was extremely difficult and even with his abilities Zuko nearly fainted many times due to overexerting himself but thanks to Iroh he managed to stay awake.
"Zuko! Do you have a plan?"
"I… do not!"
"You need to think before act!"
"I know! But I had no time my own father was trying to mark my face for a lifetime!"
"Well…. What do you want to do?"
"We'll take a ship, we'll be barely enough to command a little one I have some means to escape once we reach the ship!"
"…Zuko is it true that you know the whereabouts of the avatar?"
"Yes! He is in the south pole frozen in an iceberg"
"Froz…. I believe you we need to escape as fast as possible!"
"…Uncle do you think you can command the ship alone for a while?"
"Uh… I think so but what are you planning to do?"
"This!"
Then Zuko used the vibration concept to turn the floor in lava, this managed to keep away everyone this was enough to scare everyone but the next was even worse, he then begin to use waterbending moves and the lava was moving!
Since the lava had some of Zuko's fire energy he had some means to use it but this drained a crazy amount of energy from Zuko so he needed to do as fast as possible he the make a huge wall of lava, and then extracted the fire energy from it turning it in earth again.
Ozai and Azula were chasing them but when they saw this was enough to break them, Zuko used earthbending! How can this be possible? Maybe Zuko is the avatar?
But they didn't know that this was a earth-fire combined technique but more earth than fire so it was extremely hard to use it with just fire as a base, but this was enough to left them dumbfounded, even Iroh was speechless, he never even dared to imagine this marvelous way to use firebending!
Since Zuko retrieved some energy he used, he recovered somehow but this was not enough to escape in no more than thirty seconds their chasers would be capable of breaking through so he used the concept of speed from airbending to reduce the air resistance in him and Iroh and then used fire to fly while carrying Iroh only then they safely landed in a small ship.
"Go uncle!"
In just some breaths of time the ship was already sixty meters away from the shore, so to avoid a pursuing from the fire nation navy he extracted the heat from the water turning it into ice, the ships were now aground, so they managed to safely depart to the south pole!
[Page break]
In this chapter I tried to show some limits of the concepts, like the lavabending is extremely taxing but he manage to use a rough earthbending with help of waterbending moves, even the diminished air resistance from airbending.