Shield Operator Double Vault.

While any shield op is holding out their primary shield either standing, crouching, (or repelling but only applicable to osa since she is the only op that can repel while holding a shield out) a player from the opposing team is able to land on top of them from a vault except for when you enter the falling animation. Upon landing on them it will act like a normal surface and you can get running space and vault options. This works great in combination with Azami as you can double vault from any surface without having to place a shield down.