She-Hulk received her powers when she was exposed to gamma radiation during a blood transfusion from Bruce Banner. This caused her to transform into She-Hulk with superhuman strength and durability.
Kraven's powers come from a mix of factors. He experiments on himself with special serums and constantly challenges himself in the wilderness to develop superhuman abilities like superior reflexes and acute perception.
Photon acquired her powers in a rather complex way in the comics. It involved a combination of a rare celestial alignment and her exposure to a mysterious substance during a top-secret research project. This combination triggered a transformation within her, bestowing her with the powers associated with photons.
Deadpool got his powers through a messed-up experiment. His body was subjected to a procedure that gave him superhuman abilities, but also left him scarred and crazy.
Spiderman gets his powers after being bitten by a radioactive spider. This bite gives him enhanced strength, agility, the ability to climb walls, and a 'spider-sense'.
The Hulk got his powers through a gamma radiation accident. Bruce Banner was exposed to a huge dose of gamma rays, and that's what transformed him into the Hulk when he gets angry.