Donald J. Blake is a medical doctor and former boyfriend of Jane Foster. While still remaining in contact with Jane, Blake was married to a woman and had two twin sons who were born following the battle of New York. Due to his skills, Blake was recruited by Director Phil Coulson of S.H.I.E.L.D. and earned the rank of Level 6 throughout his career.
During the Infinity War, Donald Blake served as a one of the Avengers' loyal allies and provided his assistance to one of his favorite heroes Captain America. He traveled to Wakanda to continue operating on Vision and keep him alive for him to regain his strength and face off Thanos. He was among half of the universe' population that were killed by Thanos, who was successful in claiming all the Infinity Stones he placed on the Gauntlet.
Donald Blake dated Jane Foster, who described him as being good with patients, but bad with relationships. One of Blake's shirts, which had been borrowed by Foster and never returned, was lent to Thor while he was living with Foster during his exile to Earth. When Thor was captured by S.H.I.E.L.D. after attempting to obtain Mjølnir, Erik Selvig was able to get him released from custody by posing him as Donald Blake. Phil Coulson questioned Selvig, especially after learning that Blake was a physician, not an astrophysicist, but he allowed Thor to leave.