Emma Frost has become a central member of the X-Men over the years. With a heart of diamond and nerves of steel, she has been able to survive countless attempts to exterminate the mutants. Every time, Emma comes out with her head held high with an endless desire for vengeance. It's hard not to love a character as complex and cunning as Frost has proven herself to be.
Part of what makes Emma Frost such an incredible hero is that she didn't start that way. When she was first introduced, she was a villainous member of the Hellfire Club. While Emma has grown considerably since then, her origins are full of dark secrets, cunning betrayals, and ruthless power plays. As a villain and even while with the X-Men, Emma Frost has done some truly terrible things.
10 Murdering Firestar's Horse
When Emma Frost was still little more than a chaotic villain, she spent her time managing the Massachusetts Academy. There, she recruited as many mutants as she could. She eventually found the young Firestar and recruited her with ease. Unfortunately for them both, Emma never felt that Firestar was loyal enough. To compel her to obey, she murdered Firestar's horse in an effort to convince the hero that her fire-based powers were out of control.
Murdering a horse is one of Emma Frost's most absurdly evil acts. She found that one of her students had an animal with which she shared a true connection. The horse made Firestar genuinely happy, and Emma murdered the poor beast just to scare her. Emma is always convinced that she works in her students' best interests. Firestar is proof that it has always been a delusion.
9 Attacking The New Mutants
Firestar wasn't the only time that Emma proved she could be ruthless. Her rivalry with Professor X's school prompted her to pick on the New Mutants. On one occasion, she even built a rival team, the Hellions. After Emma captured Kitty Pryde, she forced the Hellions to face off against their Xavier's School counterparts.
This was a brutal decision for someone who always professes her love for children. Instead of teaching them to support one another in mutant solidarity, Emma Frost instead forced mutants to fight mutants. There was never any chance for the two sides to understand why they were even fighting. It was a war for the sake of war, and it made Emma a much darker character. Today, she keeps quiet about her manipulation.
8 Working For Kingpin
While Emma Frost is best known for working alongside Sebastian Shaw, she also spent years working for the Kingpin of Crime, Wilson Fisk. Under his direction, she and Elektra worked to manipulate New York City politics. Elektra would kill for Fisk, and Emma would telepathically manipulate everyone she could find.
Elektra and Emma Frost did some good while working for Fisk, but they also helped to make Fisk an overwhelmingly powerful person. If Daredevil knew what Emma had done, she would likely be the next name on the Devil's list. No matter how good her intentions are, Emma is crafty and dangerous, and it was her powers that helped give Kingpin the grasp he needed to dominate New York. In the process, he ruined Daredevil's life.
7 Wiping Iron Man's Mind
Emma Frost is preparing to marry Iron Man only a few issues after Invincible Iron Man #6 (created by Gerry Duggan, Andrea Di Vito, Bryan Valenza, and Joe Caramagna). Unfortunately, that comic issue revealed their relationship hasn't always been positive. Instead of supporting him in a time of need, Emma stole psi-blocker prototypes from his company and wiped the memory from his mind.
No matter what Emma Frost's intentions were, Iron Man is undoubtedly an iconic hero. She could have discussed her concerns about the military's psi-blockers without completely wiping his mind. Even years after joining the X-Men, Emma was content to leave his mind completely scattered. That lie followed her for years.
6 Creating The Dark Phoenix
The Dark Phoenix Saga might never have happened, if not for the Hellfire Club's influence. After Mastermind moved to corrupt the respected Jean Grey, the fate of the galaxy was forever changed. Jean became the Dark Phoenix and sacrificed her life just to stop it. As a member of the Hellfire Club, Emma Frost was directly responsible for the loss of her X-Men rival.
Of course, Emma Frost never intended to cause the destruction of a planet by corrupting Jean Grey. She was hoping to create a new enemy for the X-Men to face. Creating the actual Dark Phoenix was never her goal. Yet her actions still directly created that threat. The world may be unaware of Emma's duplicity, but she is completely implicated in the death of D'bari IV.
5 Cheating With Cyclops
To add insult to injury, Emma Frost couldn't help but make Jean's life even worse. While promising to serve as a sex therapist for Cyclops, Emma was actually working to ensure a long-term relationship with him — all while he was already married to Jean. Emma succeeded and completely ruined Cyclops and Jean's marriage.
While Cyclops is undoubtedly also at fault for the affair, it is a horrifying display of just how cruel Emma Frost could be. She knew Jean Grey loved Scott, and she was even well aware of the effect that the Phoenix was having on her. Yet Emma was happy to mask herself as Jean, just to seduce Scott. Emma's intentions are a dark secret that continues to influence Jean today.
4 Faking Cyclops' Death
Inhumans vs. X-Men was a dark event for many reasons. The Terrigen Mists were poisoning the mutants, and it was Cyclops who rallied his people against the Inhumans. While the mutants desperately fought for their survival, Cyclops eventually met his end at Black Bolt's hand. It was an honorable death that made Scott Summers a martyr.
However, his death was not quite as noble as it seemed. Emma changed the story. In reality, Cyclops died a brutal death through sickness. Emma tried to address the Inhumans problem by giving him a more deserving death. She manipulated all of her friends and marred the world's memory of Cyclops. She had good intentions, but she took away his right to be remembered as he was. Despite claiming to love him, Emma never gave him the chance to die as Scott Summers, instead of as one of the most hated characters in the comics.
3 Helped To Create Sentinels
While it was Sebastian Shaw who funded the Sentinels for the Hellfire Club, Emma Frost found his actions inspirational — even after joining the X-Men. When facing off against the Inhumans, she secretly funded Sentinels with the prime directive of exterminating the Inhumans.
Emma Frost's actions were reprehensible and showed that she was hardly any better than the Inhumans. She was perfectly happy to kill every Inhuman for the actions of only a few. Even after Medusa purged the world of the Terrigen poison, Emma was still planning to kill them all. It was a sign of how far she had fallen after Cyclops' death. Emma may be a protective person, but she went too far when trying to avenge Cyclops and her fellow mutants.
2 Taking Over Storm's Body
There is something truly terrifying about telepaths. They can corrupt a person's mind and manipulate them without anyone ever knowing. In one instance, Emma even managed to steal Storm's body and wreak havoc on the X-Men in the process. She tortured Storm and used her body to attack Storm's team.
Emma Frost has spent most of her life being controlled by the rich and powerful. The fact she was willing to do the same thing to Storm was deplorable. She knew how awful it felt to torment those she loved, but she didn't care about what Storm might feel. The two still suffer a strained relationship today, because Emma never truly made amends for the crime.
1 Taking Over The Galaxy
In a future rewritten by a Moira clone, Emma Frost once conquered the galaxy. Uninhibited by morals after being infected with Mister Sinister's genes, Emma and the Krakoan Quiet Council waged a bloody war across the known universe. They butchered entire empires and completely destroyed the Earth. Emma even led a eugenics program that forced countless mutants into servitude.
The dead universe that Emma Frost helped to create was horrific. Trillions were dead and trillions more were suffering. After the events of Sins of Sinister, Emma discovered her actions and intended to keep them a secret. She had good reason to. Just the revelation that Emma and the X-Men could take over the galaxy was enough to cause the Fall of X. Naturally, it made sense that she and the other Quiet Council members tried to keep this dark alternate future a secret.