Bending AU

Bending AU (also simply known as the Avatar AU) is an AU (Alternate Universe) within the Rise of the Brave Tangled Dragons fandom. In this AU, Rapunzel, Merida, Hiccup and Jack Frost are all part of the Avatar: The Last Airbender (and by extension, The Legend of Korra) world, and are often benders, or those capable of manipulating the four elements. Because it is not canon, ideas for this AU are shown through fanfiction, fanart, and other fan-made works. This could also be a sub-scenario for Elements AU and Dragon Warriors AU.

About the AU
The world of Avatar: The Last Airbender, being so wide and open, is a popular universe for fans to use for crossovers, especially in the RotBTD fandom. The world of Avatar is an ideal location for the Big Four to interact because of a number of reasons: the existence of magic and dragons is already well-established; the four nations of A:TLA allow for the homelands of the Big Four to be easily connected, and for each member of the Big Four to have unique, distinguishing traits; and it adds elements of competition, rivalry, and national pride between the Big Four and their friendship.

In most cases, the Big Four are each from different nations, and often are 'benders', or individuals who are able to harness the elements of earth, water, air, and fire. Since this AU is still very young, there are still many debates on exactly which nation each member belongs to.

The world of A:TLA also features an individual - the titular Avatar - who is born with the power to control all four elements. Therefore, crossovers with RotBTD often focus on one member of the Big Four being the Avatar, and the other three being bending masters that the Avatar learns from. Additionally, the character's pets are often portrayed as their guides and companions, although not always as their true form, since most creatures in the world of Avatar are seen as hybrids of animals in the real world.

The Big Four
The Big Four are often seen as members of separate nations. Although nation assignments are often debated over, general consensus can usually lower options. Below are the generally accepted nation choices of the big four:

Hiccup Horrendous Haddock III
Hiccup's place in the world of A:TLA has often been debated, but he is usually portrayed as an '''Earthbender. '''This is an ideal way of incorporating his background as a stubborn, resilient Viking. Hiccup is enduring and often willing to against the grain, but his open mind and occasional indecisiveness could result in him being a weak bender. This could be a developmental point for Hiccup where he needs to find strength in himself, and then find the strength to bend the earth. Another variation of this placement casts Hiccup as a metalbender, a spin-off of earthbending, which takes "a different kind of strength" and ties in with his skill in inventing, intelligence, and seeing opportunities - quite literally - where others do not.

Alternately, Hiccup has been portrayed as a Firebender, possibly because of the fact that he has Toothless as a companion. The Fire Nation is the only nation known to have dragons, so this plot point works really well with Hiccup's origins in How to Train Your Dragon. Additionally, his departure from the Fire Nation's stereotypical culture - which is considered rather aggressive - explains why he didn't feel he belonged, and also how he eventually changes his tribe and their ways.

Finally, Hiccup seems to be the one that fans more often pick to be the Avatar, and the conflict between his tribe's ways and his own begins to build the storyline of a journey to discover his true power. This also usually results in Toothless being portrayed as his animal companion, much like Appa to Aang and Nagga to Korra.

Jack Frost
Jack also has debated by the fans. Many argue that, based on his powers in Rise of the Guardians, he should be a Waterbender; his control over ice seems to align him with the Water Tribes. This argument can be further supported by his connection with the moon, which is the source of all Waterbenders' abilities in the A:TLA universe. However, this can be countered with the fact that many of the other Guardians also associate with the Man-in-the-Moon, and yet seem to align more closely with other nations.

Alternately, fans sometimes portray Jack as an Airbender, although it is not as popular. This is supported by the fact that Jack often travels by air, and controls his powers through his stick, just as Aang (an Airbender who was the titular Avatar in A:TLA) used his staff. Additionally, he tends to have the personality of a nomad, living alone and moving on his own to accomplish goals, all the while avoiding intense conflict. He would much rather have fun (which often was a trait shown by the Air Nomads) than fight with others.

Additionally, many fans also tends to picture Jack as the Avatar, possibly because he and Aang share many traits.

Merida DunBroch
Merida has been split into two different nations by the fans. More often, fans portray her as a Firebender, based on her strong, passionate, fiery personality. Also, Merida has a royal family, and since the Fire Nation is full of many nobles, the connection can be strengthened. Alternately, some fans see Merida as an Earthbender. This could be because she is stubborn and strong-willed, two powerful traits that earthbenders have that give them strength. It also could be because of her connection with the earth and her love of being outdoors and part of nature.

Rapunzel Corona
Rapunzel is one of the most wildly debated Big Four members in terms of her placement in the world of A:TLA, as she seems to be easily placed into all four nations. However, the most popular placement for her has been as an Airbender. This could be the fact that her spirit is free and full of respect for all life, and she is always moving and appreciating the things around her. As a Nomad in one of the temples, her exploration of the world could be easily rationalized as she travels away from her home.

Alternately, she has been placed as a Waterbender for her healing powers, often shown as part of the Northern Tribe. Her story can easily translate into that of the Lost Princess of the North, and her healing powers in many aspects define her circumstances and so who she is as a person, which renders this idea a little more legitimate.

Others have made her an Earthbender because she was 'born' from a flower, because her element is often thought of as spring, and because she loves the ground and is always barefoot. However, her nature would not be strong enough in the beginning to be able to use the element of earth.

Finally, some have even placed her as a Firebender, because Pascal could be seen as related to dragons, and also because of her connection to the sun. Because of this latter reason, she has also been seen as a member of the Sun Warriors.

Rapunzel is also a popular character to be shown as the Avatar, most likely because of the fact her hair already glows when she sings, so it is possible she could hold greater power as well.

Princess Anna of Arendelle
Anna is mostly known as a Firebender  because of her hair and the fact that most fans would prefer Anna have fire powers since her sister Elsa has ice powers, to provide a handy juxtaposition. This also could be because she is strong willed and never gives up to find help, since she is filled with such hope.

In other circumstances, Anna is not a bender at all, given the lack of magical powers she has in the film in comparison to her sister.

Queen Elsa of Arendelle
The most popular placement for Elsa is that of a Waterbender, for many of the same reasons as Jack above. Also much like Jack, fans like to portray the primordial strength of her power as a blessing from the moon spirit, explaining the color of her hair similar to Princess Yue.

Guardians
The guardians are portrayed as past Avatars, leaders of the nations, teachers or spirits that help the Avatar. North a Waterbender, that was once an Avatar of the Northern Water Tribe or the leader of the tribe. Aster Earthbender or a forest/earth spirit in the form of a rabbit. Sandy a sand/earthbender or a spirit of dreams. Tooth a Airbender, Avatar or a spirit of Hummingbirds, Memories or Past Lives. They can even be members of the White Lotus.

Kristoff Bjorgman
Kristoff is mostly seen as a Waterbender because of his love for ice and selling it with Sven or an Earthbender from his time growing up with the Trolls (which can be portrayed as spirits).

Hiro Hamada
Hiro is popular placed as a Waterbender (or Firebender  with his brother) and the Avatar, as he learns the other elements and saves the world with his friends. Fans have also cast him as Bolin from The Legend of Korra.

Leafmen
The Leafmen's' green armor, ridding 'birds' and moving around the forest with easy casts them as Earthbenders, with Tara as the Earth Queen of the Earth Kingdom. While their archery skills makes members of the Yuyan Archers.

Wreck-It Ralph
Ralph would most likely be cast as an Earthbender because of his tendency to walk barefoot and stubborn personality. He may also be cast as Pipsqueak of the Freedom Fighters due to his immense size.

The Croods
The Croods' tendency to walk barefoot and live in earthy, open areas would most likely cast them as Earthbenders who most likely would live in the open plains of the Earth Kingdom. Since they already live in a world populated by hybrid animals (like the Bear Owl and Douglas), it would be easy to bring them and many kinds of creatures into the Avatar universe.

Fanfiction

 * The Broken Four by Falki
 * Together Foreverby Little.StarBabe
 * The Elements by urchingavroche
 * The Big Four Benders by Bebuzzu
 * The Four Bender Guardians by MikaBlueStar323
 * The Big FourAvatar Crossover by xRockattitude
 * The Big Four Avatar Au by Walter Lee
 * The Lost Avatar: Introduction
 * The Lost Avatar: Prologue- The Runaway Bride by venthegolddomwriter
 * The Lost Avatar- 1:2 by venthegolddomwriter
 * Strange Alliances by Icepoppy
 * Elsa The Avatar by DauntlessCake29

Videos

 * Jack Frost - Korra - Rapunzel - Katara- No Light, No Light (the Big Four) by TheChoosenFighter