The Stone part of the design was mostly a left over concept that I asked Kap about and he never really raised issue with it, it was more a make up for the fact that I can't do the original Gorgon stare and was also a nod to an older idea where I was going from the Myth of Galatea for his appearance, I guess I could do without it, could just replace it with something else.

"So is he slow, or is he speedy?"

Slow, but have you ever heard the comment about a particularly large fighter who is a sort of lumbering giant, but is described as "remarkably agile for his size"? To raise a point, Kap's character would run circles around him with ease and not even break a sweat, but if you get too close to him -say decided to run up to him and punch him in the face- he will pick up speed alarmingly.

In regards to the Shifter forms of appearance, I made a distinction between two variants of Medusa, mainly, his first form is the much more human in its shape, 'cept it has scales, glowy eyes and snakes for hair, asides from that its physically human. The second stage is more of a serpentine appearance comparable to the "Clash of the Titans" depiction in the sense that the upper body is human, but all below that is snake.

The poisons immobility effect is because, well, its a bloody neurotoxin, it attacks your nervous system:

"The most common effect of the neurotoxins used by organisms is rapid-setting paralysis, useful to snakes and other venomous predators as it keeps the prey from running away."

The gaseous cloud is a close range weapon also, it can't be projected except from a couple of feet in front of him, in which case you're sort of fucked anyway.

As for wilderness survival, he pretty much only knows theory, not actual practice. He'd struggle a fair bit regardless.