NRS-dedicated content creator MK_REO has put together a quick demonstration on how to apply Supergirl’s F+3 in Injustice 2 in knockdown situations.
Supergirl’s big overhead can be manually controlled during the rising animation. Since the character has several ways to land a hard knockdown (many of which are combo-enders!), this means she can constantly apply which-way coin flips on opponents. The move is safe on block, and it can also be charged to beat delayed wakeup timings. Players that love themselves some vortex heavy game-play should consider trying out the Kryptonian Warrior for this reason alone.