One afternoon in Chelsea, during New York Fashion Week, Feng pulls up to a runway event looking like a hungover college freshman. The 19-year-old, part of an emerging wave of UK underground rap getting hyped up like the ’03 NBA draft class, has bags under his eyes. His hair is in a messy bun. He’s wearing a wrinkled white tee, a colorful scarf he bought off Depop, black skinny jeans, and house slippers with the heads of stuffed teddy bears on the top. He glances at the world of high fashion—a