Summons a blizzard of stone shards to attack Luke

Now it was the Dark Lord who initiated the assault. Luke found himself forced steadily backward as
Vader threw an unceasing blizzard of stone shards and saber cuts at him. It was impossible to counter
them all.

Somehow Luke did so.

They were circling in the center of the temple floor now. Lying on her side, the Princess tried to turn
and watch. The pain of her wounds rose about her like a steel wall. Around her thoughts the wall
closed, and in response her eyes closed and she slumped back to the cold, cold stone.

Again the two enemies paused, only now it was Vader who was panting heavily. "Kenobi... trained
you... well," the Dark Lord admitted admiringly. Some of his usual insouciance had been drained by
the steady fighting. "And you have some... natural ability of your own. You have proven a challenge. I
enjoy... a challenge."

Splinter of the Mind's Eye, Chapter XII, 122