Mostly Nash and Hall since the NWO was their and Bischoff's baby.And it made WCW profitable for the first time. Also created wrestling best boom period since the 80s and who was responsible for that.
Hogan jumped in and it was a great run for a bit but then he fucked everything up being a key part of why WCW destroyed themselves.
And, of course, credit has to go to everyone in WWE with responding and eventually taking everything to new heights.
But all credit to the original heel turn and the first part of the NWO run. Hogan was doing good work for a bit, there.