(Haylie, just jump in whenever. And Lana, don't forget I need you to TG my character. XD)
When Keith cried out in confusion, he may or may not have caught onto the fact that the pitch of his voice was changing, escalating, becoming more girlish overall as his voice box was exposed to the chemicals that were spread by the gas. His muscles began to diminish as his face slowly began smooth over and take a feminine quality. His nose, for example, shrunk while his lips became fuller and his eyes wider. It was at this point that a pressure building at his chest just couldn't take it anymore, and two rather large breasts forced their way out, straining against his shirt, which seemed to be getting cut lower and lower with every passing moment. The sleeves of his shirt seemingly separated from the torso, and the material began expanding down his arms, feminizing the arm as it did so. The material eventually wrapped itself around Keith's hand, entrapping and transforming his fingers into a daintier version of themselves. He most likely would have been distracted by other changes at this point, but that didn't change that his hair was changing colour to an orange-blond lengthening to just beyond his shoulders, but it was tying itself into two pigtails using red ribbons. His shirt pretty much wasn't a regular shirt anymore, as it was cut right below his breasts, apparently only there to cover them and expose his midriff, while the top had taken on a black and red colour. It also didn't look like there was any bra action going on... His wardrobe had been taking a matching change down below, as his pants had been slowly been taking on the form of a black and red skirt that was fitting nicely around his hips and butt, which had just finished expanding to feminine proportions as well. The hair was all gone from his legs, which had thinned out as well, and his feet were now smaller and encased in a pair of black shoes.
Go team! The finishing touches came with the appearance of pom poms in her hands, as well as a sudden mindset that made her want to be peppier than usual.