First, im aware this is an old piece, but i love this to no end. i am a great fan of short animations and this is easily the top of my list.

second, in response to @Evilgrapez :

while i can say that the characters introduction is short and their time as well, you learn quite a bit about them.

Sparker is a fast paced and energetic character who is easily amused and friendly, while Aquanna is graceful, calm, and shy.

You can gather these things from their facial expressions, movements, and their element.

as for the story, its spontaneous and while slightly confusing, i think has a quite explainable plot. Lets start from Aquannas death and Sparkers fury.

Sparkers fury is linked to both his element (as fire is associated with rage and anger) and Aquannas death. even though they had very little interactions, a bond was clearly formed. His rage unlocks the classic "harm someones love, indestructible vengeance mode activate" scenario. (something ive found extremely common in characters i create based on my personality lol, as well as a common hero archtype)

after that he unlocks hidden potential/power and destroys the strange mechanical castle. After this we have the scene with the exoskeleton that becomes human (although not certain.).

my interpenetration is quite simple, but in my mind meaningful. the exoskeleton isnt exactly explainable, but it somehow was created from the ruins of the castle. the flames that burn th castle are the remnants of Sparker, and they bind to the exoskeleton forming a body. as it begins to rain, a symbol of Aquanna, it cools the body and forms the skin. this causes both fire and water to become one and able to be together. back in the beginning Sparker and Aquanna had attempted to hold hands but could not because touching fire to water had hurt them (maybe.).

well, thats my view on it.