Delaying tactic

The sixth-order Black Nightmare Spider screamed, and its figure blurred in the air, leaving only a few afterimages. The fish-scale whip and Rusk Cunning's blazing fire sword hit nothing, and the afterimages were shattered, but it did not gain any advantage.
A strong wind came from behind, and Rusk Cunning heart shuddered. He didn't expect the speed of this black nightmare spider to be so fast. It was in a position to be attacked before, but in the blink of an eye it had circled behind them. It...