Here is how the originators, the Protopopovs, performed the FO death spiral:
A little stuttery on Ludmilla's part as she is descending, but then a thing of beauty. I have wondered whether this pair were able to make this difficult move work because they are both so tall. Maybe there is some physics at work that makes this a difficult move for skaters of disparate heights to perform? I speculate that getting down into the FO death spiral is dicey because if the woman gets too far forward on her skating foot, she risks tripping on her toe pick. The woman has to be balanced very precisely throughout. (But, I have never done a death spiral of any kind, so am just speculating.

)
If you back the video up to 4:20, you can watch a program that consists of nothing but death spirals! And exquisite skating, of course.