As the stone enclosed him, Bryce quickly extinguished his flames, and his body began leaking the acid much more rapidly. The acid would quickly chew apart the grenade, and be added to his energy pool for the morph ahead, as well as the bullets fired. Instead of burning straight down, the acid clung to the walls all around him, melting it down for fuel.
His body quickly began converting itself, using the stone as a cocoon to grow into a more appropriate form. His body enlongated, grew together. the glands that usually produced sweat regeared, producing a mucous that would quickly weaken stone and rock, making it weak and malleable. his head became a single entity, with a four hinged jaw growing on the crown of his head. His legs tapered together into a tail, and his teeth grew and multiplied to break apart stone. Along his body, grooves grew where at the twitch of a muscle they would shoot out rows and rows of neverending spikes. A stomach grew that could hold a tall man whole, and layers of small spikes replaced the acids in the stomach to churn the prey up once caught.
Once this metamorphosis was complete, the acid would chew until only a few inches of rock remained to hold Bryce.
OoC: Finally finished a history project that's been gnawing at my time for attention. Praise [insert god of choice here] and may [insert god of choice here] give me strength.