Yeah, it’s called a Grav-Con Unit. What it does is, like what Lightning is shown doing at the beginning, it creates a barrier that allows its user to manipulate the gravity around them. It shows up again after the opening FMV when Sazh inadvertently destroys it, when PSICOM ambushes Snow in Lake Bresha, and when the party storms Eden.
If you’ve played Dissidia 012, this is also part of Lightning’s EX mode, in which her Grav-Con Unit activates and protects her from slamming into walls and floors.
