Marcelo Gaia describes himself as “one of the world’s biggest fast-fashion designers” — but he says it’s entirely against his will. Gaia is the owner and lead designer of the womenswear brand Mirror Palais, a trendy upscale label. But he claims that his original, proprietary designs have been cash cows for fast-fashion brands like Shein that allegedly rip off his styles — and for the influencers who make commissions promoting them. “Independent designers are the…