The sea witch seems pretty perturbed by the group in front of... it? He/she holds up a hand to instruct the to stop and goes in order. "First of all, here," they say, and gives Virmir a slight *jzap* of weird green electricity. With it, he can feel some semblance of vocal cords forming, allowing him to speak again.
"Next." They gesture at their table in a sweeping motion. "I've been studying the old religions and cities of the sea, seeing as there's pretty little to do up here in my tower. The old arena near here - which I'm sure is what you were referencing, vorzh-man, or surfacer as you may have been before - has since been stolen over by skum and their eldritch leaders, the aboleth. I think you might have seen one or two of them, based on what I could see of your recent memories. Anyway, the arena was part of a greater nation before belonging to a race of shapeshifters. Their name has been lost to history; their abilities have not. I'm theorizing here - and this is a working theory - that the intense magic, stress, and collection of unique races and backgrounds provoked latent magic and imbued it into you four. It just so happens that the stress, physical pain, and magic bring out that sort of change due to what first bound it to you."
They take a deep breath and point at Attor. "It's entirely possible that you won't change at all and completely refute my theory, but I would think that you'll be experiencing a similar change when you come close to death."
"Now, it's also possible that these skum and aboleth were what bound the unwilling changes to you as well. Maybe some sort of odd idea of forced evolution wormed into their heads from some elder gods. Regardless," they finish, "you will find more answers back in that arena, if that is what you wish. With this odd sort of enhancement, I don't think you will be perishing from anything but starvation, disease, and old age anymore."
They cast something else, and transparent manacles bind around your wrists and ankles. The magical chains connect to each other. They don't limit your movement or body in any way UNLESS someone moves too far from the group as a whole. The sea witch beams. "To prevent any of you from ditching the rest. I need these answers as much as you all do. You will return with the knowledge you learn. I will write amazing scrolls on the topic and spread tales of your heroism. And, of course, I will work on formulating some sort of dispell for this enhancement, should you want it. Is there anything else before you head back? Gear, food, a harem?"