Bulbapedia Wrote:The target will move next on the current turn, ignoring priority.

• If the target has already moved on the same turn, After You fails.
  
• If the order remains the same after using After You, After You fails.
  

• Negative Priority Moves;
  After You can be used to "lift up" the priority of low priority moves like Trick Room, Circle Through, Focus Punch, etc etc.
  
• Slow Pokemon;
  Sometimes the slowest Pokemon are also the hardest hitting. Case in point, Excavalier. Excavalier will, under most circumstances, go last. However, if a fast Pokemon like Lopunny where to use After You, Excavalier will, most likely, go second in the priority bracket, instead of last.
  
• Smeargle;
  While this Pokemon potentially fits the two categories above, there are so many ways Smeargle can benefit from an After You Pokemon. One example is a Smeargle Lopunny lead. Lopunny uses After You, and the Smeargle uses Dark Void, and both opponents fall asleep.
  

• Lopunny/Mega Lopunny
  Mega Lopunny is the fastest user of After You, and is without a doubt the best. It has a base speed of 135, making it the 12th fastest Pokemon tied with Mega Manetric. Few things outspeed Mega Lopunny, and fewer non-Scarfed Pokemon when Following Battle Spot rules. Lopunny has a base speed of 105.
  
• Swoobat
  Swoobat is the fastest non mega Pokemon, with a base speed of 114, making it the 49th fastest Pokemon.
  
• Aromatisse
  Is your Mega Pokemon fast, but not fast enough to outspeed big threats? Does Trick Room fit your Team? Well, Aromatisse can cover both Trick Room and After You. With a base speed of 29, you will almost always be going first in Trick Room. With the Aroma Veil ability, you cannot be Taunted, and so you can freely use Trick Room to your heart's content.