at noble gas,the best way to fly to barbadoes ,book a ticket with emirate to reodejenero via dubai and when u get to brazil emirate is gonna connect you to ur final destination no transit visa is required,and be very carefull in the airport cuz brazilians can be strict when it comes to nigerians, cuz i saw many guys deported back to nija while i was at d airport. and i will advice make sure you have other supporting document before travelling. that a country is visa free that does not mean u should walk straight to the airport and fly any time u feel like. i will advise u seek for bahamas visa instead.