Come on guys, Ogun didn't bite the dust like that after being stated that all fire users got a power up in their flame factor after the cataclysm getting near. This was stated after Shinra came back from his trip to the past, and if I'm not mistaken the third generation users got the greatest power up since they can produce flames. This fight is far from over.
I'm pretty sure Charon grasped the idea of Ogun turning off his flames before his fists could make contact with him in the hopes of not giving Charon any flames to absorb, just pure kinetic energy from his fists riding the momentum from his flames.