Yes, Bruce Banner is known to us all as the original and massive Green Goliath, the Hulk in the Marvel Comics, and he has gone through a lot of upgrades over the past few years. But he is no longer the most powerful version of this superhero.
According to an all-new issue of the Avengers series by Jason Aaron, this title goes to Jennifer Walters.
In one arc of Avengers, Thor and Jennifer Walters had consumed the Blood of Ymir, and this had caused them to grow into huge sizes and fight all the Celestials. This experience, coupled with the exposure to massive levels of radiation and also the Celestial beings had left Hulk with a lot of side effects.
While in the Hulk form, Jennifer is seen losing control over herself, and while this is difficult for Jennifer, it makes her the most powerful Hulk in the entire Marvel universe.
In the issue, Avengers #8, the character, Doctor Strange had studied Jennifer, and he had tried to figure out what had changed inside her body. The Sorcerer Supreme had then been super shocked with all the results.
“You’re the Hulk. Your body is already rife with Gamma radiation to kill most people many times over,” Strange had said.
“And since your encounter with the Celestials, those Gamma counts have skyrocketed. Your body is now storing more Gamma energy than ever before. And it appears you’re sometimes able to release that energy…in the most explosive of ways.”
After having learned this, Jennifer then admits that the levels of radiation are making her away more explosive than the otherHulks.
“That explains the changes to my physique,” Jennifer had said.
“And the increased power levels. God, you’re right, that sort of explosiveness is beyond what even Bruce can generate.”
Bruce Banner had been seen making his way back from the world of the dead in the series of Immortal Hulk, but now he is not the strongest there is.