Shine spike

From SmashWiki, the Super Smash Bros. wiki

The Shine spike is one of Fox's edge-guarding techniques. It consists of using Fox's down B to spike an opponent who is already off of the stage, down and away, to prevent their recovery. The Shine spike is especially effective, because the Shine has set knockback and stun, making it as capable at zero percent as it is at two hundred percent. Also, since the move slows Fox's vertical movement, it allows him to easily recover after spiking.