6th Gen Master Ball in ORAS

[Guest123_x1]

I went ahead and used the Master Ball on Deoxys. Although I had Rayquaza with me at the time of that battle, I decided not to put too much wear on it or my other Pokémon (which were all several levels behind Rayquaza.)
Kind of like the strategy players were often told to use concerning Mewtwo in Red/Blue/Yellow.

 

[alesk8ter]

I used mine on Deoxys. When im playing, i dont like to read walkthrough or guides about the pokemon game im playing, i feel like they're spoiling me, and Deoxys got me for surprise, after a battle with that Rayquaza I was about to save but Rayquaza asks me for ride him, of course I accept, the save part can wait i though, later it takes me to space and the rest is history. Then I had a relationship with that Rayquaza, until Nintendo Network gives me a Shiny one, then our love goes off and I have to broke up with it. It stills over there in my PokeBank.

 

[Aisu]

I used it on Kyogre, come to find out I should've used it on Deoxys, who was so adamant on my catching it that it Struggle'd to death.

 

[HOAT]

I am yet to use it. I catch all pokémon with regular Poké Balls

 

[akaMike]

I'm saving mine for Deoxys. Seems like the best use for it.

 

[Midi]

I used mine on Deoxys. It outleveled everything I had at that point, and I didn't want to bother catching Rayquaza and fighting Zinnia again, even though I knew that this Rayquaza has a really high catch rate. If I could save between those fights, I would definitely hold onto my Master Ball.

 

[Desert Stream~]

I still have 7 I beleive. I haven't used any yet, and I keep trading them from other games.
Rayquaza and Deoxys were easy to catch, caught them with the first ball each.