As a model put on a pair of cat-eye, upswept sunglasses to finish a Versus look—a "ballerina" dress in black with a silver chain-mail bib covering the breasts—Christopher Kane stood back and, in mock awe, exclaimed, "Look out, she's going to slay you!" Kane was dressing girls backstage before his first presentation in the Versace Teatro in Milan, where models were being placed on plinths to display the 25 wool, lace, and laser-cut neoprene dresses he's designed for his Versus ready-to-wear debut. Donatella Versace herself was walking around looking over the group of black, mushroom, and sizzling red dresses, one detailed with slashes held together with pink, red, and green aluminum safety pins—a junior reinvention of the dress that famously made Elizabeth Hurley's career in 1994. "It's sexy without being over-sexy, and that's difficult to do," said Ms. Versace, heaping praise on the young London-based Scot who worshipped Gianni Versace, watching him on satellite TV as a kid.

The dresses, constructed with Chantilly lace stretched over cutouts, some with fan-pleated skirts and neoprene trimmings, aren't literal revivals, though Kane's heroine sent him to study her brother's work, and her own, in the family archives. Kane's favorite detail is what he calls an "arm support"—a cutaway sleeve so technically tricky he says he'd never have been able to make it back home in East London. "The pattern cutters here are amazing," he marveled. "I just have to do a sketch, and the dress comes back perfect." (Only the sunglasses are vintage Versus, retrieved from stock made in 1999 and certain to be a big seller.) Despite numerous requests, buyers had not yet seen the results of the relationship that started in 2006, when Ms. Versace donated chain mail to the student who was desperate to source the hard-to-find material for his master's graduation show. There's plenty of chain mail in a couple of the Versus dresses, too, but the boss swears prices will be reasonable. "It's a young collection," she growled. "I make it a young price."