I have only vague memories of the 1981-1983 Spider-Man and His Amazing Friends cartoon, which featured the new character of Firestar in place of the Human Torch due to licensing issues. Firestar, whose real name was Angelica Jones, got her first canon appearance in the Marvel Universe in an issue of X-Men a few years later, immediately followed by a four-issue limited series to explain her origin.
My notes on Issue # 1 say "very good, despite DeFalco!" I've always thought of Tom DeFalco as a bog-standard comics writer with mostly forgettable stories and villains, but this story worked really well. We're introduced to thirteen year old Angelica Jones as she starts a new school because she, her father, and her grandmother just moved. Angelica's first day goes well, until she meets a trio of fellow students who could be the inspiration for "Mean Girls." There's some sort of weird ice-block carving competition that Angelica is extremely excited about. Ice is limited (?), and the Mean Girls are so mean that Angelica has a true Carrie moment and starts releasing microwave radiation which damages the ice sculptures. She runs home, terrified at the first release of her powers, and finds that her grandmother has had a heart attack and died! The incidents are completely unrelated, but Angelica and her Dad are so despondent that they're easy prey for Emma Frost, who detected the mutant energies and offers Angelica a place at the Massachusetts Academy. Xavier, monitoring Cerebro, arrives as well, but is minutes too late. Angelica has already signed with Frost.
Issue # 2 fast-forwards four months, as Angelica undergoes training in the secret basement complex underneath Frost's Massachusetts Academy. She has some run-ins with the Hellions, but Frost keeps her mostly away from that established team. Frost gradually puts Angelica through various tests to gauge the extent of her power, while simultaneously subtly training her to fear the X-Men. Frost's ultimate goal is revealed: she wants to craft Angelica into a super-assassin! Meanwhile, Angelica is lonely and sad to be away from her father. She finds solace in long rides on her favourite horse. During a big dance, in which the kids (New Mutants) from Xavier's school are invited to attend as well, Frost manipulates things so that Angelica panics, sets fires to the stables, and kills her beloved horse. It's all a bid to drive Angelica further and further into Frost's grasp by making her afraid to use her powers without further training.
Issue # 3 jumps forward again; Angelica is now 15. Frost continues training sessions in her version of the Danger Room, but has the robotic enemies that pop up take the form of the X-Men. Moreso, she gifts Angelica with a bracelet that causes fearful hallucinations. One of Frost's guards charged with escorting Angelica and keeping watch over her, Randall Chase, starts to feel very protective of his charge. Later, after a brief visit home doesn't go well because Angelica's dad is fearful of her new powers, Frost stages an attack at the airport to force Angelica to use her mutant powers and lash out. Frost's ultimate plan is revealed: she intends to use Angelica as a weapon to kill the Black Queen!
Issue # 4 is set a year later. Frost stages a purported assassination attempt by the Black Queen, in order to get Angelica to defend her and swear vengeance, which the girl does. Frost and Sebastian Shaw, the Black King, finalize plans for their weapon to attack the Black Queen during a formal dance. Randall Chase, however, figures out that his boss is manipulating Angelica and rushes to tell her the truth. He's caught though (hard to betray a mind-reader!) and Frost tells Angelica that he's been murdered by the Black Queen. In fact, Chase is alive but imprisoned. On the night of the formal, he escapes, though badly wounded, and manages to tell Angelica, before dying, that Frost is her real enemy. Enraged, Angelica attacks Frost and barely refrains from killing her; instead, she destroys the entire complex underneath the Massachusetts Academy and returns home to her father.
"Good stuff, well written!" my notes say. I like the main character, I like the supporting cast, and as an origin story, it works quite well. Frost is a great manipulator and someone you don't want for an enemy, and you could imagine Firestar getting involved with the New Mutants or X-Men for years of good stories. From Wikipedia, it doesn't sound like she really appeared all that often after this, but for once I can honestly say something wasn't Tom DeFalco's fault.