The world's mightiest girl!


Basic Info

Real Name: Cassandra “Cassie” Clark.
Age: 16
Nationality: United States of America
Hometown: Ellsworth, Indiana
Species: Female Human [Mutagenic]


  • Superhuman Strength: Hyper-Girl is extremely powerful, able to lift up to approximately 1.6 tons. However, she is capable—through sheer force of will—to lift up to 16 tons when she focuses, though she cannot do so for long and doing so exhausts her.
  • Invulnerability: Through exposure to her cousin’s cosmic power source, her body is nearly impervious to harm and capable of surviving in almost any extreme environment.
  • Flight: Hyper-Girl can fly at speeds of up to 400 mph, though her control is somewhat finicky.
  • Limited Healing Factor: While she cannot control it, Hyper-Girl is capable of healing from grievous injuries. This seems to be a reflexive ability that only activates when she is dangerously injured.
  • Enhanced Senses: Hyper-Girl is capable of seeing various forms of radiation. She can also see into many different spectrums of light, including X-Ray vision.
  • Enhanced Reflexes: While her reflexes and coordination are not at superhuman levels, they are considerably higher than they were before she got her powers.

Hyper-Girl is friendly, brave and intelligent. She is likeable and tends to get along well with others, though she’s very awkward and a little weird. Growing up as isolated as she was, Cassie loves people but has trouble connecting with them or recognizing normal social norms.

Of all the team, she’s been doing the job for the shortest amount of time, but what she lacks in experience she more than makes up for in heart and resourcefulness. Her intelligence allows her to think outside the box and when combined with her determination, Cassie is the premier researcher on the team, as well as the only one who actually likes monitor-duty.

She loves being a part of the team, though she can be a little paranoid about being accepted by her peers. She’s careful not to divulge too much information about her past to her new teammates lest they think differently of her.

Cassie has a good relationship with her cousin Hyperion, who she looks up to as a role-model and something of a big brother. He’s an example to most superheroes around the world and she is no exception.

Overall, Cassie is a real hero with a big heart and endless determination to do the right thing.


Cassie was born in Ellsworth, Indiana to a farming family. Her life was pretty idyllic growing up and her cousin Jonathan’s family was only a few miles down the road, so she saw them often.

When she was about seven years old, however, Cassie was diagnosed with MacGregor’s Syndrome: a genetic, blood-born defect that creates fluid build up in the lungs, which leads to oxygen deprivation and multi-system organ failure. While treatments helped, Cassie was left her weak and bedridden for much of her life. She became cut off from other children her age. Much of her free time was spent reading in her room. Her father was determined to help her have something as close to a normal life as he could, so he took her fishing and swimming at a nearby lake. As she grew older (and weaker), Cassie developed a love of science and, for her fourteenth birthday, received her very own laptop, which she quickly customized and optimized. Despite her disease, Cassie remained an optimistic young girl who idolized the Guardians, specifically the mighty hero Hyperion.

Just after her sixteenth birthday, however, Cassie’s condition took a turn for the worst. The doctors determined the treatments would no longer be able to help and that “at this point, the most we can do is make her comfortable”. Cassie’s father refused to accept this, however, and spent much of his savings trying to find some way to save his daughter.

Salvation came in the form of an experimental new treatment that would involve draining her almost entirely of blood and replacing a few of her internal organs with artificial, modular ones. She would have to repeat the procedure once or twice per year but that wasn’t an issue for Cassie’s family.

What was an issue, however, was Cassie’s blood type; she possessed a very rare quirk in her blood that made it nearly impossible to have a normal transfusion process, even with a matching blood-type. Providence would step in once again when her older cousin Jonathan was discovered to have the same blood quirk and agreed to the transfusion.

However, Jonathan’s blood turned out to have more of an effect than anybody could have known. Cassie recovered almost immediately following the transfusion. What’s more, she was in better physical condition than she’d ever been in; she was trim and had the build of a marathon runner. Not bad for a girl who spent most of her life in bed.

Cassie also found she possessed incredible strength, the ability to fly and more. In an effort to help her understand what happened to her, Jonathan revealed that he was actually the superhero Hyperion and that his blood contained unknown cosmic energies that seemed to have given her powers similar to his.

Thrilled to be a “superhero”, she trained for six months under Hyperion to understand her new abilities. She was excited to begin her work as a superhero but Hyperion warned her that doing so would put her family in danger. After some discussion, it was decided that she would move to Emerald City to begin her hero-in career as a part of the team of Sidekicks put together only a few weeks before by other members of the Guardians.

Taking on the name Hyper-Girl, Cassie received her costume from her cousin and set out to start her new career save the world. She just hopes she’s up to it.


Sidekicks MagicRoog