Burning Down the House
In Madelyne's case, getting revenge on everyone who has wronged her (Scott, for abandoning her, Mister Sinister, for cloning her and then trying to have her killed, and Jean Grey, just for getting there first) means thoroughly embracing her own derivative status to the point of weaponizing it. She seems determined to become the demonic inversion of all the various manifestations of Jean Grey. In her dreams, she is depicted surrounded by flames, forming a shape that comes just slightly short of the Phoenix raptor, but Madelyne will channel the flames outward: again and again, she lampshades the crossover event by declaring she will start an "inferno." Her "Goblin Queen" outfit is so revealing that it makes Jean's Black Queen fetish garb look like a nun's habit (only powerful telekinesis could possibly explain how she doesn't fall out of it). When she can't have Scott, she settles for his cast-off younger brother. If, cloned and fast-grown in a creche, she was denied a real childhood, she kidnaps babies to use as a sacrifice. If she can't raise her own baby, she'll sacrifice him as well. And, like Rachel right before assuming the mantle of the Phoenix, Madelyne is compelled to visit Jean's (empty) grave. Surrounded by memories of Scott bidding Jean's grave a farewell, and of their wedding , she destroys the headstone: "Why did you have to ruin everything? /Why couldn't you have stayed dead?!? ("Strike the Match," Uncanny X-Men 240, by Claremont, Silvestri, and Green).
Her tantrum is witnessed by Jean's parents, who paradoxically know their daughter so well that they can't be sure Madelyne isn't actually their eldest come back from the grave;
Elaine: John--that woman--could it be Jean?
John: I don't know, Elaine. She had so many incarnations.
John has a point, even if he his phrasing sounds unlike anything that would actually be spoken aloud. The X-Men universe abounds with telekinetic redheads, and throwing energy bolts while looking maniacal is definitely on-brand. Madelyne transforms the Greys into a pair of demons who will serve her throughout the course of the crossover, a completely superfluous plot point that is nonetheless thematically resonant. Madelyne is determined to both have and ruin everything that Jean had. At the end of her confrontation with Mister Sinister, the villain who cloned her, inadvertently caused her to be awakened by a shard of the Phoenix force, gave her false memories, and put her in Scott's path in the hopes that they would breed, she gives a speech that establishes her as the anti-Phoenix:
Phoenix: Hear me, X-Men! No longer am I the woman you knew! I am Fire and Life incarnate! Now and forever - I am PHOENIX!” (X-Men 101)
Goblin Queen (to Mister Sinister): Your ambition is a world to rule.
In one strike I make it ashes.
I abjure life, "Father"--
--and give myself over whole and unreservedly to the fire!
An inferno...
....that will consumer you all! ("Fan the Flames," Uncanny X-Men 241, by Claremont, Silvestri, and Green).
I think it’s safe to say that Maddie is in her “Villain Era”
Where Phoenix is fire, the Goblin Queen starts a fire. Where Phoenix is "life incarnate," the Goblin Queen "abjures life." The Phoenix is a force of destruction and renewal, while Madelyne, in her new identity as the Goblin Queen, is interested only in destruction. The Phoenix also embodies the endless iterability of plot (how many times she has died and come back), while the Goblin Queen's role is to finally put years of convoluted plotlines to rest. Madelyne is the ashes out of which the Phoenix can rise again, or, to put it in a less flowery manner, she is collateral damage. And she is angry.
Next: Limbo Needs Women