Avengers AU

 Avengers AU (also known as Marvel AU) is a popular AU (Alternate Universe) within the Rise of the Brave Tangled Dragons fandom. In the AU, Rapunzel, Merida, Hiccup and Jack Frost are super-powered men and women within the Marvel Universe. As it is not canon, ideas for this AU are shown through fanfiction, fanart, and other fan-made works. This can be considered a sub-scenario of the Superhero AU.

About the AU
This AU portrays as the four as a group of meta-humans (normal human beings embedded with extraordinary powers) that team up in a world of superheroes and super villains. As the name implies, this AU most commonly places them in the Marvel Cinematic Universe, though this is not required.

The world of Marvel has been a popular universe for fans to use for crossovers, considering the lack of restrictions the universe has on magic and powers. The Avengers Initiative is a prime place for the Big Four to appear in the universe because of a number of reasons: it has a focus of combining many powers for one ultimate goal, it allows for the use of magic and the idea of dragons, and it adds action and adventure to really spice up a story.

Jack Frost
Jack Frost, because his legend originates from Norse Mythology (Jokul Frosti), is often seen as an Asgardian in the same manner as Thor, or maybe his foes the Frost Giants. Another common interpretation places him in the role of Tony Stark (AKA Iron Man) for his carefree attitude, power of flight and mischeivous streak. In more common instances, Jack is sometimes portrayed as the Son of Loki  and brother to Elsa. In the crossover for the TV show Agents of S.H.I.E.L.D, he is portrayed as Agent Ward. Jack is also portrayed as Quicksilver (when Merida or his little sister is the Scarlet Witch), Deadpool, Mr. Fantastic and The Human Torch.

The Guardian Stone can be used as one of the six Infinity Stones or contain one, like how the Mind Stone was hidden within the gem that "powered" Loki's Scepter.

Rapunzel Corona
Rapunzel is seen mostly as Captain America for her bravery and her goodness. In Agents of S.H.I.E.L.D, she is Jemma Simmons, due to her excitable and smart personality. Fans have also cast her as the Scarlet Witch and The Invisible Woman.

Merida DunBroch
Merida seems to serve as Hawkeye in this AU, because of her skills of archery. A common interpretation portrays Merida as Hawkeye and Black Widow's daughter, possessing her father's skills in archery and her mother's red hair. Fans have also cast her as Black Widow (herself) and the Scarlet Witch. In Agents of S.H.I.E.L.D, she is portrayed as Skye due to similar personalities.

Hiccup Horrendous Haddock III
Much like Jack, Hiccup's identity in the AU is interchangeable between an Asgardian like Thor (due to his Viking heritage) or Iron Man (for his intellect and skills at crafting). Some fan art has also portrayed Hiccup as Bruce Banner (both are intelligent) and Toothless as '''The Hulk. In the TV show Agents of S.H.I.E.L.D, he is portrayed as Leo Fitz''', due to their high intelligence and engineering skills. He is also portrayed as Mr. Fantastic or The Human Torch from The Fantastic Four and the web swinging, spider like superhero, Spiderman.

Queen Elsa of Arendelle
Ever since the creation of the fan-made internet-video How Frozen Should Have Ended, many fans like to believe Elsa to be a mutant. Much like the mutants of the Marvel Universe, Elsa holds a deep fear of prejudice for having powers she was born with, and has much difficulty controlling these powers to the degree that it could hurt innocent bystanders. In context with The Avengers, many people compare Elsa to Scarlet Witch. In more common instances, Elsa is sometimes portrayed as the Daughter of Loki and sister to Jack.

Pitch Black
Because of his manipulative nature, longevity and tragic origins, Pitch Black is most often portrayed as the trickster god Loki.

On a side note, some people consider Loki to be a humanized version of Pitch, which justifies Elski as being apart of the pairing Cold and Dark.

Hiro Hamada and Baymax
Occasionally, Hiro and Baymax are inserted into the story in the place of Iron Man. Baymax is like the suit itself, being able to fly and being a robot, whereas Hiro is like Tony Stark, being the genius inventor that thinks of all kinds of cool gadgets to upgrade Baymax.

Hiro using his skills in science to help him in his hero work and still goes to school also casts him as Peter Paker, A.K.A. Spiderman, with Violet or Riley as Mary Janeor or Gwen Stacy.

Wreck-It Ralph
Ralph is known for his huge size, anger issues, and destructive power that leaves him ashamed of himself. This, coupled with everyone's view of him as a monster and attempted learning to control his power, would make it easy for writers to cast him as The Hulk.

Violet Parr
Violet's invisibility and force field powers and being a older sibling heavily resembles and casts her as the Invisible Woman from The Fantastic Four. She is also seen as the Scarlet Witch, for having a brother with super speed powers.

Guardians of Childhood
The Guardians of Childhood are commonly seen as the Guardians of the Galaxy and the Avengers Team.

Fanfiction

 * Call in the Children: Avengers by Annaliese95
 * Frozen Hearts and Minds by Forrestib
 * The Big Four & Marvel by adrian.chavezramos
 * Meeting the Seasons by SimplyMe51
 * Avengers: The Big Four by KayHawkGirl
 * To Guard What You Love by JackieFrost1234
 * Days Of The Future by KnifeInTheCrayonBox
 * RotBTD the Avengers by ddogirl
 * Loki's Son by The Amber Fury
 * Gifted by EmJx
 * RotBTD the Avengers! by ddogirl
 * Rogue of the Night by KillerGeishaYumi

Videos

 * The Big Four: Guardians of the Galaxy Trailer by katherined
 * How Frozen Should Have Ended - Reissued by How It Should Have Ended
 * Rise of the Brave Tangled Dragons: Agents of S.H.I.E.L.D. by Stephanie King 15
 * The Amazing Spiderman 2 CGI Style by Brixie Ann
 * HTTYD ~ Guardians of the Galaxy *Mock Trailer* by Nina Kuhar
 * Captain America Civil War Trailer Non/Disney Style by Dreamcatcher 2
 * Doctor Strange Trailer Non/Disney Style by Dreamcatcher 2
 * Doctor Strange Non Disney trailer by The snow princess