Soul Cleansing Pill.

Unlike the bed of flowers and herbs he had seen in the garden of Zhu Ru Shi's house, Master Wu's garden had just grass, well, at least it used to. The trodden footprints on the surface had almost turned it into a mud pit. Just a few thick blades remained poking out.

"Attack." Master Wu said.

"You want me to attack you?" Li Jun questioned him.

"That's what I said, isn't it?" Master Wu sighed.

Li Jun smiled. 'You don't need to ask me twice.' He thought as he dashed forward and swung his sword in a low circular arch towards Master Wu's stomach. 

"Wrong." Master Wu said as Li Jun's blade came to an abrupt stop.

The hilt rattled in his hands, and the collision made his hands numb. It felt almost like he had hit a rock. Immovable and impenetrable. Li Jun looked down and gasped; Master Wu hadn't even made an attempt to block; he let the sword hit him. It tore his clothes but didn't do anything to him at all.