Sailor Moon AU

Sailor Moon AU is an alternate universe usually within the Rise of the Brave Tangled Dragons universe, but also with Rise of the Brave Tangled Frozen Dragons universe. In the AU, Rapunzel, Merida, Hiccup, and Jack are all part of Sailor Moon world and often have powers based off the planets. The ideas are often shown through fanfiction, fanart, and other fan-made works.

About the AU
The world of Sailor Moon, being so wide and open, is a popular universe for fans to use for crossovers, especially in the RotBTD fandom. The world of Sailor Moon is an ideal location for the Big Four to interact because of a few reasons: the existence of magic is not known, so only to the chosen ones; their powers are based off planets; and they are easily connected since they live in Japan. Also 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 designed to save Earth from dark forces.

The Big Four
The Big Four are often seen as Sailor Heroes in order to protect Earth from evil forces. It is kind of debated, but here are the ones that are most settled on.

Hiccup Horrendous Haddock III
He is mostly Sailor Jupiter, since he has a bond with his dragon Toothless, and since the powers are Thunder and Strength, they associate him because of his personality.

Jack Frost
He is widlely debated. Because of his ice powers most people associate him with Sailor Mercury, and that ice is a frozen version of water. The powers are Water and Wisdom, which most people think it fits him perfectly.

But, people also believe since Jack has the wisdom of Sailor Mercury, he should be Sailor Moon instead, because people think he would make a better leader of the group. The powers are Love and Justice, which can be another reason people think it fits him perfectly.

Also people associate him with Tuxedo Mask because of the Jackunzel pairing.

Merida DunBroch
Because of her orange hair, most people associate her as Sailor Mars, which also has fire powers which fits her perfectly because most people believe if she had powers it would be fire.

Rapunzel Corona
She is mostly asociated with Sailor Moon because of the Jackunzel pairing.

Princess Anna of Arendelle
Some people believe that since she doesn't have powers, they would mostly give her fire powers. Making her '''Sailor Mars.  But some people like to make her Sailor Moon''', because of the Janna pairing.

Queen Elsa of Arendelle
Since of her ice powers most people would put her as Sailor Mercury also, but they would likely make her Sailor Moon because of the Jelsa pairing.