Okay I'm back from a piece of crap school day.
The stage is[/is] what gets the spike to almost irrecoverable, the spike i had been questioning earlier on was like an easter egg. But the normal FF Nair spike was a very slow downward, this one (on FD and all nuetral stages, working best on SV and FD) immeadietely pushes them oblivion. It is almost impossible to recover if at all.
So here is how you do it:
When your enemy is on the ledge grabbing at a lower 100% damage ratio, or higher, come down on their side facing away from the stage with a FF nair. It oushes them with a nice force into the stage and sends them flying down. (Or on YI which sends them at a 30 degree declining angle)
I can get this spike every time it is very simple and very effective. It also works with lower percentages but i didn't want to through that out there for a trial. I'm was talking to Scat last night (haven't checked PMs today) and we were talking about him setting up a vid. But as for right now it could be a little bit later on tonight.