Ghost

"You have no idea what I'm capable of!"

- Ghost to Ant-Man

Ava Starr is the daughter of Elihas and Catherine Starr, who gained the ability to render herself intangible and generate extreme amounts of power following a quantum accident, which killed her parents. Later, she was put under Bill Foster's care, and spent her life following the accident slowly dying of a lack of quantum energy. Ava began plotting to harvest quantum energy to prolong her life, under the moniker of Ghost.

Early Life
As a child, Ava witnessed the fallout of her father's partnership with Hank Pym, who kicked him out of Pym Tech and smeared his name within the scientific community. Embittered, Elihas continued to research quantum power on his own despite the risks. When an experiment involving a Quantum Tunnel went wrong, Ava tried to run to her father to ensure he didn't die alone, but the tunnel ruptured before she reached him, killing her father and mother and inundating her with quantum energy.

When rescue crews arrived, they were unable to touch her as she had become intangible from the accident. She was placed into a shelter and first encountered Bill Foster there, who gave her a toy. Although she was upset that she was unable to hold it, Bill encouraged her to focus her powers, and she was eventually able to solidify and pick it up. Bill promised to find a way to cure her condition and began to act as a surrogate father, developing the quantum chamber to allow her to briefly stabilize and ease her pain.

Joining S.H.I.E.L.D.
Observing the potential asset her powers could become, S.H.I.E.L.D. took Ava and began to train her in espionage so that she could go on missions to take down threats that proved too difficult for conventional operatives. They developed the Ghost Suit for her as a means of harnessing her abilities, granting her the option to slip between intangible or solid states. Over the course of her time in the field as well as the prolonged suffering caused by the quantum displacement, Ava became hardened and extremely vicious, eventually leaving S.H.I.E.L.D. at an undisclosed point once her condition started to worsen.

Clashing with the Pyms
To be added

Personality
Ghost is ruthless, having been trained by S.H.I.E.L.D. to become an elite espionage agent tasked with infiltrating and eliminating criminal organizations, terrorist cells, and other threats. She holds a grudge against Hank Pym for expelling and discrediting her father, inadvertently leading to the accident that killed him and his wife as well as afflicting her with quantum disequlibrium. Due to the years of chronic pain she experienced as a result of this, she was desperate enough to do anything to permanently fix her condition, planning to extract Janet van Dyne's quantum energy despite the fact the process could potentially kill Janet and even considered kidnapping Cassie Lang as leverage to force Scott to give her the Pym laboratory. Although she shares a somewhat familial bond with Bill Foster, who assisted her in attempting to find a cure, she violently threw him aside when he tried to stop the quantum energy extraction.

However, she does show compassion when she urges Bill to abandon her, warning him that he will also be pursued by the authorities if he continues to act as her caretaker. She also appears to be on much better terms with the Pym family after Janet returns and they begin extracting quantum energy to gradually cure her quantum illness.

Powers

 * Intangibility: Ghost can phase through solid objects and living beings at will. The use of her powers is accompanied by flickering, prismatic images of her body as she quantum shifts through space. With the aid of her suit, she can choose whether to become solid or intangible, which allows to quickly evade attacks and counterattack in tandem; for example, she became intangible to drop through a table while smashing Wasp into it and phased through Hank's van before solidifying to kick Wasp onto the street during a chase. Solidifying herself while phased through solid matter presumably has destructive effects on the original object, as she threatened Hank Pym by phasing her hand through his chest.
 * Invisibility: Ghost is able to pass in and out of the visible spectrum.
 * Self-Augmentation: Ghost is able to amplify the amount of force behind her attacks while phasing, as a single kick was able to launch Ant-Man through several walls.

Abilities

 * Skilled Acrobat: Ghost is skilled with acrobats, which allowed her to vault over a car with ease. She also incorporates gymnastics and acrobatics into her fighting style as she battles opponents.
 * Skilled Combatant: Ghost possesses a degree of combative skill that allowed her to match Ant-Man and Hope van Dyne with the use of her powers.

Equipment

 * Ghost Suit: A full-body suit that was designed by S.H.I.E.L.D. to help her better control her powers. The suit allows Ghost to selectively phase through matter at will, allowing her to rapidly switch between intangibility and tangibility for both stealth and offensive purposes.
 * Quantum Energy Chamber: Created by Bill Foster, the chamber releases waves of quantum energy which temporarily stabilize Ghost's disequilibrium.

Family

 * Elihas Starr † - Father
 * Catherine Starr † - Mother
 * Bill Foster - Adoptive Father, Friend and Temporary Enemy

Allies

 * Janet van Dyne † - Attempted Victim turned Healer and Ally
 * Scott Lang/Ant-Man - Enemy turned Ally
 * Hope van Dyne/Wasp † - Enemy turned Ally
 * Hank Pym † - Enemy turned Ally

Enemies

 * Sonny Burch
 * Uzman
 * Stoltz † - Victim

Trivia

 * In the comics, the Ghost was a male anticapitalist saboteur who went unnamed. A brilliant inventor, he created a battle suit with his personally designed GhostTech that allowed himself or any object he touched to become invisible or intangible.
 * The Ghost is the third character in the Marvel Cinematic Universe to be depicted as a different gender from their counterpart in the comics, following Jeryn Hogarth and The Ancient One.
 * Ghost is the second female main antagonist in a Marvel Cinematic Universe film, the first being Hela.
 * Ghost is also the second main villain in a Marvel Cinematic Universe film who became good, the first being Winter Soldier.

Behind the Scenes

 * Ghost's first name was originally listed as Dawn.
 * Tamiko Brownlee was a stunt double for Hannah John-Kamen in the role of Ghost.
 * Eli Logue was a stand-in for Hannah John-Kamen in the role of Ghost.