Warning: Spoilers for Fate: The Winx Saga season 1 are ahead.
We need to talk about Rosalind (Lesley Sharp). Fate: The Winx Saga ended with Rosalind staging a coup at Alfea and getting ready to sink her claws into Bloom (Abigail Cowen) — but why? Rosalind's actual plan on Fate: The Winx Saga remains a total mystery through the end of the finale, "A Fanatic Heart," but there are clues throughout the season that suggest that Rosalind's evil plans have only just begun.
For a moment in the finale, it looked like Rosalind might might not be the villain she was set up to be. As she explained to Mrs. Dowling (Eve Best), all of her actions have been, she claims, to prepare the next generation for a coming war. Her explanations, however, aren't too convincing, especially considering she murders Mrs. Dowling right after her big speech. She might think she's a hero getting ready to save the realm, but Rosalind has way too many secrets and too much blood on her hands to be a good guy. And if she's a villain, she needs a motive.
Rosalind claims she's motivated by a desire to keep Alfea and the fairies safe, telling Dowling, "The Burned Ones are nothing compared to what's coming." And it certainly looks like she's going to refocus Alfea to be more of a military academy than a regular boarding school. But, again, there's way too much secrecy around this unnamed threat for it to be her only reason for killing Dowling. If she really wanted to protect the fairies, she could just tell them what's coming, but she doesn't. Instead she lies, manipulates, and, when all else fails, kills to get her way.
Clearly, Rosalind is a power-hungry maniac who enjoys playing with the fates of others. It's what led to her downfall 16 years ago, when she manipulated Dowling, Silva (Robert James-Collier), and Professor Harvey (Alex Macqueen) into killing a town full of innocent people. (She insisted to Bloom that the villagers were evil Blood Witches, but she's also a pathological liar. And, even if that were true, it still doesn't explain why she lied to her team in the first place.) Bottom line: she can't be trusted, which means that everything she told Bloom and Dowling about the Dragon Flame, the Burned Ones, and this upcoming war should be taken with a huge grain of salt. In fact, just dump out the entire salt shaker.
Assuming Rosalind can't be trusted might actually be the key to discovering her true intentions. As Headmistress during the war, she led the fight against the Burned Ones, culminating in the destruction of Aster Dell. But what if that was her endgame all along? Rosalind tells Bloom that she saw the nuking of Aster Dell as hitting two birds with one stone, taking care of the Burned Ones and the Blood Witches with one precise strike. She also used that event to kidnap Beatrix (Sadie Soverall) and Bloom while faking the death of one of her generals, Andreas (Ken Duken).
These are not the actions of an innocent woman. Aster Dell was always a target for Rosalind; she was just using the Burned Ones as an excuse to strike. Even more nefarious — we know that Rosalind unleashed the Burned Ones onto Alfea to test Bloom's powers, suggesting she might be able to control them. Who's to say she didn't send the Burned Ones to Aster Dell specifically so that she could kill the Blood Witches who lived there? And if she did, in fact, manufacture an entire war to kill one town of people, then it's likely she's gearing up to do the exact same thing again.
So what's her target? Well, it's probably not Solaria, the realm where Fate is set. There are also six other realms in the magical Otherworld, and, given the lack of unified government, Rosalind could be gearing up for a war with any one of them. The most likely scenario, however, is that it has something to do with witches.
In the show, Rosalind clearly sets up witches to be the enemy, something that mirrors a plot point of the original Winx cartoon, which included a trio of evil witches called the Trix. If Fate: The Winx Saga returns for season 2, and the writers want to dive into a bit more of the original lore, then witches are a pretty solid potential villain. Unless Rosalind tells Bloom they're going to fight witches. Whatever Rosalind is really up to, she's not telling anyone.