Mega Rayquaza
Zacian
The name said it all. Anything goes. Nothing gets banned, and literally anything is allowed. This tier was created way back in Generation 6 when Mega Rayquaza was released. Here, you can use literally anything you want, from all the overpowered Megas and Legendaries to just bunch of meme Pokemon. Because of this, this format is the most popular among Pokemon Youtubers.