When he left Morgan Stanley to join SoftBank Group in Tokyo in 2015, Alex Clavel had little in common with the swashbuckling dealmakers who surrounded CEO Masayoshi Son.

After years of executive departures and soured bets, including a $16 billion investment in co-working space firm WeWork, the 49-year-old former tech investment banker is Son's top lieutenant leading SoftBank's attempt at a turnaround.

As the co-CEO of SoftBank Investment Advisers, Clavel is responsible for managing investments for the firm's $160 billion Vision Funds and another $35 billion on the group's balance sheet.