Avengers AU

 The Avengers 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.

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.

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. 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.

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.

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

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