Who is Tony Bellew’s opponent Oleksandr Usyk?

Tony Bellew comes in as an underdog against Oleksandr Usyk on Saturday, but how did the latter become the undisputed cruiserweight champion? Oleksandr Usyk and Tony Bellew go head to head in Manchester on Saturday, with the Ukrainian's status as the undisputed world cruiserweight champion on the line. The 31-year-old holds four belts and has …