Mutating was traumatic to Godzilla and it changed how his disability affects him.
Godzilla’s mutation actually gave him mobility he didn’t have before. Pre-mutation, his arms were almost useless by early adulthood due to contractures despite his dad’s best efforts to help him exercise them.
Clenching one’s fists tight takes effort, right? Clenched fists are Godzilla’s default. He uses that same clenching effort to open his fingers. They never really relax. His parents (when both were alive) taught him to keep his hands open and wiggle his fingers every now and then so they don’t get stuck as clenched fists. It became a habit, so he does it more or less without thinking even after his mutation.
The same effort didn’t transfer to his arms, unfortunately. They were curling up tighter and atrophying from contractures as he aged, but the mutation process changed that. His hands still really, really, really ‘want’ to be in fists all the time.
Post-mutation Godzilla has pretty decent hand dexterity and opposable thumbs. It’s easier for him to grasp things than it is to let go of them. Few realize the focused effort he puts into using his hands because he makes moving them look easy. It’s not. There is no incidence of moving his body that’s easy for him, but he doesn’t see it as effort because it’s his normal.
The mutation from a godzillasaur into Godzilla pushed his bones and muscles into a new formation, which is why he stands upright instead of tilted forward. Of course, this caused a different setup of mobility issues.
Godzilla was pretty much comatose when the Futurians teleported him somewhere else in time. He regained consciousness when he landed on spent radioactive waste on the seafloor, which caused a bright flash of light. Then he passed out again and finally woke up to the pain of his body mutating.
He felt his internal organs changing. He felt his bones and muscles stretching. His skin / scales literally split like ripped clothes because of his rapid growth and his hide grew back as keloid-like scar tissue, giving it a pitted appearance. His whole surface feels like a big scab and it’s his biggest, most visible scar.
Godzilla spent several days totally deaf and blind because his eyes, ears and brain were the last parts of him to complete the mutation process. He crawled around on the seafloor like Kamata-kun from Shin Godzilla until he realized he could use his arms again.
He had to figure out the tingly feeling in the roof of his mouth meant Sustenance was nearby, and he had to learn he could absorb it by touching it.
He made himself sick eating dirt off the seafloor for awhile because he got hungry while his stomach was still changing. He threw up a lot of blood during that time because he was experiencing radiation poisoning that healed as fast as it harmed due to his mutated healing abilities.
He ran fevers. He couldn’t eat. He had seizures as his neurons multiplied, which damaged his redeveloping brain as much as the chronic hypoxia that affected him in his youth.
The most painful part aside from muscular-skeletal growth was the formation of his nuclear gland that acts like his internal nuclear reactor. It’s actually cancer that his body adapted to keep him alive instead of kill him, and his radioactivity prevents it from metastasizing to kill him the way cancer normally kills. That organ tore a lot of nerves and forced his internal organs to rearrange around it. It leeches nutrients from his body if he doesn’t absorb enough radiation to keep cell division and cell death on an even keel. He can temporarily get around this by eating meat like he used to, such as whales, but it’s not long-term sustainable.
Walking became more difficult. His legs were in a new position and his center of gravity moved to a slightly different place. He never wholly gets used to that, so he loses his balance a lot.
He was still mastering his ability to walk again when he showed up on Japan’s shores in 1984. Sadly, the humans didn’t understand him when he asked if they saw his dad. Instead, he ended up in a volcano. He got a lot of practice walking while stuck in Mt. Mihara, so he was better at it when he emerged from there later.
The mutation process is an extremely traumatic memory for Godzilla, and he remembers every conscious second of it due to his hyperthymestic memory. It’s why being thrust into darkness against his will terrifies him; he thinks any darkness he doesn’t go into himself will hurt.
If you want to see Godzilla freak out into a terrified panic, let him go to sleep somewhere with light and wake him up in pitch darkness. He’ll screech. He’ll vomit due to the psychosomatic association, crap all over himself and flail around, slamming into things he can’t see as he scrambles to find a source of light.
The trauma is so intense to him that he temporarily forgets he can create his own light. He feels phantom pains like the pain he felt when his whole body changed. Then his heartbeat goes wonky, which triggers more pain, which triggers even more freaking out until he loses consciousness or spits out his atomic beam and assures himself that he can still see something.
The tiniest speck of light will turn off the panic reaction in the snap of a finger. He’ll cry when the fear passes.
The worst part is the meddling of the Futurians deprived him of his dad’s comfort during it all. They went through it together on the island before the Futurians got involved. His dad held his hand through the whole thing even though he was in terrible pain himself.
Instead, they got separated. The ‘54 Goji went ashore looking for his missing son and died for his efforts. Godzilla turned up in ‘84 looking for his missing dad and got dropped in a volcano for his efforts.
Godzilla is very aware of what he’s become because of the Change. He relived it all when he saw Shindo’s face inside his own reflection. It’s why he gave that deep, tired, sad sigh.
He knows what he is and that he can’t be what he was.
