But you didn't answer the question: Who is killing the US Dollar?

It is 7.5 Billion people who have been been fleeced by the giant ponzi scheme that is the central banking system and run by the global banking cabal. The demise was started by the BRICS (creating a parallel finance / trade system that does not rely on USD as the key currency) and this decimation of the dollar will be finished by the blockchain as financial assets flee the centralized ponzi institutions and desperately enter the cryptocurrency market.