Agent 33 (real name Kara) was a former S.H.I.E.L.D. agent. She was brainwashed by Daniel Whitehall into serving HYDRA. After agent Grant Ward helped her regain her identity and freedom, she allied herself with Ward. Agent 33 also has the ability to shapeshift due to the Nano Mask.
Kara Palamas was a loyal S.H.I.E.L.D. agent until it was revealed that HYDRA was still active. When the war between SHIELD and HYDRA began, she took refuge in a safehouse. However, Palamas was located by HYDRA, after Agent Bobbi Morse gave her whereabouts to HYDRA. Daniel Whitehall using the Faustus method persuaded her to comply various missions for him. On one of these missions, she was disfigured by Melinda May after her Nano mask melted on her.
As she saved Grant Ward from an imminent death, he wanted to thank repairing the Photstatic Veil. Agent 33 and Ward went to a restaurant to kidnap Selwyn, the creator of Photostatic Veil. When Ward returned to apartment after killing Selwyn, she takes Skye's appearance to thank Ward for the favor but he rejects her, since he no longer feels attracted to Skye. Later, they both went to a military base to kidnap Sunil Bakshi and take revenge on him for what he did to Agent 33. Having kidnapped Bakshi, Ward and Kara used the same method that HYDRA used to brainwash Agent 33.
Ward and Kara went to S.H.I.E.L.D.'s base to help Coulson to take down HYDRA, Gonzalez put custody on both because he distrusted of them. While her stay, Palamas told Morse about her love for Grant Ward and promised they would see him for the man she knew. Later, Ward called Coulson to inform him that he would leave Kara with them in order to help her psychologically as she deserved forgiveness. However, this was a plan devised by Ward and her to kidnap Bobbi Morse and take revenge on her. Eventually they were located by Lance Hunter and Melinda May, which led to a fight between them. She was killed by Ward after he confused her with Agent May.