He's a specialist in bankruptcy and liquidation administration. Essentially the debtors have appointed him to take over and identify what can be sold or salvaged. He gets paid out of whatever funds he can find.
I’m surprised the debtors assumed control of the company that quickly though. Figured it would take some time to play out
Ofc, if I lend $100m to a company that you control, and you start siphoning that money into your bank account...then you aren't going to declare bankruptcy until the stealing is finished. So there are provisions to claw back money even ex-post (i.e. time doesn't matter) when someone has committed a crime...but the idea is that bankruptcies are wrapped up quickly because the longer it goes on the more value is lost by everyone (apart from lawyers)...speedy liquidation is also a central component of a well-functioning capitalist economy.
”Debtors” are people that owe money (i.e., here, the FTX family of corps).
This is not a case where the creditors (the people to whom money is owed) are in possession (or even yet identified), though that can happen in bankruptcy.