My best Earth Grade pill?

"Little brother… that was too strong," Liu Xin said as he tried to stand still, his head still hurting a bit. 

Alex looked at Liu Xin, feeling a little guilty. "I'm sorry, Senior Brother. I should have told you when I was going to attack," he said with a hint of sadness in his voice. 

"It's okay. In fact, it's better this way since I get to see the actual effect of the attack. And I must say, it's stronger than I would've expected. However, are you sure you can win against the disciples in the higher realms?" he asked.

"Higher realms? Wouldn't this work well against anyone without spiritual sense?" he asked.