It is revealed that all superpowers come from Compound V, a drug invented by Nazi scientists; a low-powered version mixed with cocaine is called Blue, and it is used to attain a singular, powerful high (or, as revealed during the surveillance, allows prostitutes to endure or recover from sex with superhumans), but it carries a risk of spontaneous and horrifying mutations. Judging that he is suitable to join the team, Butcher injects Hughie with a specially formulated mix of V that gives him super-strength and durability--much to Hughie's chagrin.
Butcher
Hughie