Josephine Thomas (Earth-616)

Josephine Thomas (Infectia) was the daughter of a geneticist based in a Manhattan brownstone. As a result, she was better able to comprehend the nature of her mutant power. Upon her father's death, Josephine inherited his brownstone, his laboratory, and a fortune; after receiving her inheritance, she dropped out of high school.

Eventually, Josephine saved Beast with her mutant abilities but contracted the Legacy Virus. She died, despite Beast's efforts to save her.

Powers
Biological manipulation: Josephine was a mutant with the superhuman ability to perceive the molecular structure of living beings and to induce mutations in other living beings by altering them genetically. Apparently, she must be in physical contact with a living being in order to induce such changes. In each known instance in which she mutated another human being, she did so by kissing them, although it is unclear if she had to kiss others to mutate them.

Josephine could mentally perceive the molecular structure of living beings and, hence, could control the mutation processes she induced. The people she mutated were altered into their new forms within seconds, often growing tremendously in size in the process, accumulating extra mass from an unknown, perhaps extradimensional, source.

Those Josephine has mutated possessed vast superhuman strength, but their strength eventually wore off, causing them to disintegrate. The more quickly the mutated beings expended their strength, the faster they would burn out and die.