Originally posted by Stoic
It didn't make him less powerful in terms of having an object of power, but he was possessed by the Serpent like Cain was, when we saw him shackled up, and pushed behind the Serpents more dominant soul. The Hulk broke free of Nuls control later on after his battle with Thor, but while doing battle with Thor it wasn't banner in the drivers seat. Rulk, She Hulk, Betty, Skaar, Abom, and The Abomination can not amplify their strength nor could Nul Hulk, unless someone has proof that Nul had the ability to go World Breaker like the Green Skar could. With the knowledge of the Serpents Heralds being evil to the very core, if Nul could have gone World Breaker, and killed millions of innocents then he would have done so long before his battle with Thor, or even during his battle with Thor. This did not happen. What we saw was a Nul possessed Hulk unable to tap into the host bodies dynamic strength powers. The healing factor, speed and other powers that naturally come with being the Hulk are just passive powers, but the actual strength amping ability is a conscious one. Only Banner can do this. Oh and Lyra sort of.
That actually isn't true.
Cain was just letting the Serpent control him, he could have broken free at any moment. It also stated that a portion on Cain was in control which is why he walking instead of flying. This was stated in the same Thunderbolts issue Stoic is referencing.
Also let's look at the other Worthy.
Look angrir, I can't remember who but someone close enough to him to survive. He said Ben was afraid, not Angrir but Ben.
Look at the exchange between Nul Hulk and Thor.
When Thor says "I could never beat you."
Nul HUlk replied, "I always knew." Not Hulk always knew but I was the word used.
The characters persona were not locked away and pushed aside, they were still very much there and still very much out at front. They were just sharing and combined with the spirits.
Wasn't it Hulk who also said Nul is Hulk's anger given shape. I would guess that means Nul was plenty angry.