Sushil Modi already wears three hats: he's the head of the Bihar BJP, the state's deputy chief minister and the finance minister of Bihar. Soon, he'll have to wear one more, as the head of a committee of state finance ministers to pilot India's biggest tax reform in decades - cutting through the clutter of hundreds of indirect taxes, to a unified goods and services tax (GST). Modi will replace Asim Dasgupta, the former finance minister of West Bengal, but it's unlikely that this assignment will be a bed of roses for the Bihar politician.