Ever since Disney officially announced they are working on "Frozen 2," the studios have been quiet regarding its cast and plot. There isn't even a definitive release date although there is a MovieInsider listing for an untitled Disney animation film scheduled for March 9, 2018, which could be the release date for "Frozen 2." 

Despite the scarcity of information, Movie Pilot  speculates that the next film may feature not just a primary villain — which many rumors suggest will be a fire-based sorcerer that can counter Elsa's ice-based capabilities — but also a secondary antagonist in the person of Anna. 

The report looks back at the original "Snow Queen" fairy tale on which "Frozen" is based, and compares what elements the first film took and what elements were either changed or eliminated. 

In the original fairy tale, the Ice Queen and her trolls are villains but this was altered in "Frozen" so that they can be relatable heroes. The key plotpoint in the first film, however, is that Anna's heart gets frozen, right in the introduction, and it is the reason why the king and queen separate young Anna and young Elsa. 

MoviePilot cites that the original tales' Gerda and Kai represent Kristoff and Anna, respectively. The report continues to explain that in the fairy tale, the frozen heart causes Gerda to only see the ugly and bad side of things until Kai comes to the rescue. 

It is possible that Anna's frozen heart may later cause her to turn slightly evil and see only the ugly aspects of life, therefore turning her away from her sister and friends. This will cause some strife with Elsa who may need Anna's help against the rumored fire villain. 

However, as reported by Australian Network News, these are just speculations and unconfirmed plot points until Disney releases an official synopsis or trailer for the film.