He goes down, but he rolls when he hits, tumbling back up to his feet in a seamless movement. And as he bounces down and up, he realizes that the other Kevin is approaching from behind. He catches a glimpse of him in his peripheral vision, sidling up with his sword ready. It occurs to him that the other one might intend to drive him toward Lacie's Chains, or at least trap him between the two of them.

No.

Darting around, he grabs his doppleganger and hauls him around, essentially using him as a human shield. The other one laughs when he realizes what's happening. It won't work as well as he's hoping, but Lacie will have to slow down now, be a little more careful to avoid striking her own lover. That will help.