A new breed of e-cigarette has addicted teenagers and confounded regulators worldwide by offering flavors like Blue Cotton Candy and Pink Lemonade in a cheap, disposable package. The tycoon dominating this latest wave is Zhang Shengwei, 50, a veteran of China’s vape industry in the southern manufacturing hub of Shenzhen. Zhang quietly rose over 15 years from a boutique exporter to become one of the world’s largest vape manufacturers.