Well, Aang being the Avatar has a deep connection with the elements. In this fanfiction, perhaps he enters the Avatar State and uses all his elemental powers in harmony. He could use waterbending to create moisture and cool the volcano, combined with his airbending to disperse the heat and gases.
Well, in this fanfiction, it could be the way the author describes the volcano itself. It's not just a background setting but almost a character. And Aang's interaction with it is very detailed. The emotions and thoughts that go into his attempts to calm it, the challenges he faces that are different from typical Avatar challenges like fighting bad guys. It gives a fresh perspective on Aang's role as the Avatar, making it stand out among other Avatar fanfictions.
It's likely Aang would win. He has the power of airbending which can be used to create barriers and move quickly. Also, if he taps into the other elements like waterbending to cool the lava, he has a good chance of overpowering the volcano.
In 'aang vs volcano fanfiction', Aang might use his airbending skills to try and counter the intense heat and lava of the volcano. Maybe he would create a large air current to divert the lava flow.
In some fanfictions, Aang's connection to his past lives plays a crucial role. He could draw on the wisdom and skills of previous Avatars. They might guide him on how to defeat Azula specifically. He could learn a new bending technique from one of his past lives that gives him an edge over Azula's firebending, like a unique way of using water to extinguish her most powerful fire blasts.
In some fanfics, Aang might die in battle against a powerful enemy. He gives his all but is ultimately overpowered.
He might start by observing. Aang is a curious person, so he'd likely watch how people live, how they interact with technology. He may also try to find other benders to learn about any new developments in bending. And he'd probably use his kind heart to make friends easily in this new future environment.
Aang might go into a deep state of depression. He has always been an emotional character, and having his heart broken by Katara, someone he loves deeply, could send him into a downward spiral. He might isolate himself from his friends and stop practicing his bending for a while.
In fanfiction, a dragon knight in a volcanic setting can make for a very exciting story. The dragon knight could be on a quest related to the volcano, like finding a rare treasure hidden within it. The heat and danger of the volcano add an element of high - stakes adventure.
The survivor might have had some prior knowledge about volcanic eruptions. This knowledge could have guided them on what to do, such as not running towards the lava flow but rather perpendicular to it. They also could have been part of a group that worked together to find safety. By helping each other, looking out for signs of danger, and sharing resources like water or cloth to cover their faces from the ash, they increased their chances of survival.
They might have also had some basic survival knowledge. Knowing which way the wind was blowing, for example, so they could avoid the path of the ash cloud. And also having the physical stamina to keep running and moving until they reached a relatively safer area. They had to endure the harsh conditions, like the heat, the choking ash, and the fear, but their will to live pushed them through.