[Wild Goose]

In addition to what Craxuan was saying,

Spoiler for Difference in scene between anime and light novel:

In the Light Novel, Asuna goes up against the Army and does a repeat of what she did against Kuradeel, attacking with all her might (as opposed to slowly repeatedly using Linear, which is what she did here). Three minutes later, all members of the Army in the vicinity are lying on the ground, stunned, thanks to repeated application of knockback effect.

The player protection code prevents you from taking damage, but the physics engine is still simulating the effects of a sword hitting you at extremely high speed.