In Pokemon ruby destiny What is the first legendary you catch?

There is no official Pokemon game called "Pokemon Ruby Destiny." It is possible that you are referring to a fan-made game or a ROM hack.

To determine the first legendary Pokemon you can catch in your specific game, you'll need to provide the following information:

* The full name of the game you are playing.

* The specific version of the game you are playing. (e.g., Pokemon Ruby Destiny v1.0)

* The location and circumstances of the legendary encounter.

Once you provide these details, I can help you figure out which legendary Pokemon you can catch first.