Beat the Invisible Enemy!
Rukia and Chad are fighting the Hollow who was hunting the young boy's soul. Chad cannot see the Hollow but he can sense it and attacks it. Rukia can see the Hollow, but since she still has none of her Soul Reaper powers her attacks have no effect. A little while into the fight Ichigo appears and starts fighting the Hollow. When Ichigo defeats this Hollow it is sent to Hell and not the Soul Society because the soul slayer can only cleanse sins after death not ones during life.