How do you get 2 masterballs in Pokemon emerald?

You can't get two Master Balls in Pokemon Emerald legitimately. There's only one available in the entire game, which you receive from the Contest Spectacular in Slateport City after winning the Master Rank in all five contest categories.

However, there are ways to obtain more Master Balls through glitches or external tools:

Glitches:

* Game Shark or Action Replay: These devices allow you to modify the game's data, including adding more Master Balls.

* Save File Editing: With a save file editor, you can modify the save file and add as many Master Balls as you want.

External Tools:

* ROM Hacking: You can edit the game's code to increase the amount of Master Balls available in the game.

Important Note: Using glitches or external tools can be considered cheating and may impact your enjoyment of the game. It's recommended to play the game as intended and appreciate the scarcity of such powerful items.