Samuel Abraham works as assistant to scientist David Shield on I-Island. He is an older, heavier-set man with short blond hair and blue eyes, usually kept closed, dressed in business attire: a suit, tie, slacks, suspenders, and dress shoes.

Initially appearing goodhearted, Samuel collaborated with David to create the Quirk Amplification Device—a headset designed to safely boost a user's Quirk. When I-Island's sponsors halted their research over safety concerns and seized the device, Samuel protested alongside David, but failed. Resentful over the lost recognition and financial rewards, he blamed David. Samuel then devised a plan to steal back the device by staging a fake villain attack, secretly hiring the criminal Wolfram and his men to ensure his compensation.

During the I-Expo incident, Samuel accompanied David to the storage vault under the guise of being hostages. Together, they unlocked the vault holding their invention. Upon the arrival of David's daughter Melissa Shield and Izuku Midoriya, Samuel revealed his betrayal, summoning Wolfram and handing him the device. Wolfram immediately double-crossed Samuel, shooting him. David took the bullet to save Samuel's life, leaving Samuel shocked and questioning David's motivation.

Samuel's fate following these events remains unknown, with no subsequent appearances or developments documented.