The Fifth Element; An Adventure Time Fanfic (sometimes shortened to simply The Fifth Element) is an AU Fanfic of Adventure Time, written by https://www.fanfiction.net/u/2324681/ConnerWithARailgun
The fanfic takes place in an alternate Land of Ooo, one that is eternally locked in warfare and a shortage of resources by four superpowers, The Elemental Kingdoms. Each kingdom provides only one resource, and they all must raid the other three to survive. Politics are shakey, but Ooo is in an uneasy balance. However, the balance of power is tipped when Simon, the Ice Elemental, finds a frozen human in his territory.
The fanfic takes it's ques from shonen anime, with epic fight scenes and a narrative that is divided up into "Arcs". As of 2018, there are currently 3 arcs.
The Boy In the Ice Arc, telling the story of Simon first finding Finn, frozen beneath a glacier. Finn awakes, revealing his amnesia and his talent for violence.
- Adaptational Badass: Simon Petrikov and The Flame King are the Ice and Fire Elementals in this version of Ooo, as opposed to Patience St. Pim and Flame Princess. Simon is repeatedly implied to be a walking nuke, and it is pretty much spelled out that while the other three superpowers have armies and advanced technology, the mere fact that Simon is alive and kicking is enough to act as a deterrent. The Flame King is also talked up pretty big, but he's still said to be no match for Simon in a straight fight.
- Lemonjon is also pretty badass here. He is able to single-handedly raid the Fire Kingdom's capital city, defeat the Flame King in single combat, and give Finn and his allies a pretty good run for their money.
- Ascended Extra: Many major characters are minor characters in the main canon. Finn's allies Frosty Bob and Stag were a background character and a one-shot antagonist in the show.
- Big Bad: The Mother Gum, the ruthless matriarch of the Candy Kingdom.
- Big Good: The Ice King, being Finn's protector and surrogate father figure.
- Elemental Powers: There are four elements, plus an unknown fifth one. Simon and The Flame King are both extremely powerful because of their mastery of their abilities.
- Guys Smash, Girls Shoot: Of Finn's party, Finn, Stag and Frosty Bob are all physical fighters, who use a Super Mode, Super Speed and Shapeshifter Weapon powers respectively. Huntress Wizard and the Flame Princess used ranged based attacks.
- Human Popsicle: The Ice King finds Finn frozen in a glacier. Finn's amnesia means he has no idea how he came to be frozen solid. However Finn was definitely born in Ooo, and was evidently frozen very recently
- The Juggernaut: Lemonnaut spends the latter half of the Flame Kingdom Arc doing nothing but soaking up damage, and even the combined might of every Flame Person in Corona City doesn't appear to slow him down. He only seems to slow down after tanking a couple of hits from Finn's Super-Mode.
- Last of His Kind: Finn and, in a way, The Ice King. Simon evidently considered himself human in the past, but is currently unsure as to whether or not he still counts.
- Speed Blitz: This is Stag's preferred mode of attack. Being a Fragile Speedster, Stag cannot take too many hits and he knows it, so he rather wisely attempts to get in as many attacks in as possible. In his fight with Finn, The Stag hands the human his first defeat, by being pretty much untouchable.
- Super Mode: Finn, Huntress Wizard and The Train possess a form of this, in which the skin turns red, and the body starts to exhaust a lot of steam. This mode apparently increases Strength, Speed and Agility 100x fold, and either makes the user able to ignore pain. It also pretty much switches off the user's higher brain functions, and while in this state, Finn is incredibly violent, and can barely tell who's friend or foe. This is apparently the result of growing up in The Fight Kingdom