i don't have the game but if there are ultra balls i think those would be good[i caught groundon in soulsilver with 3 ultraballs!]
You catch it in a reagular pokeball, dirtbag.
You should use a quick ball. If that doesn't work lower it's health and chuck ultra balls
The best ball is the mast ball, but if you want to save it use the quik ball. If you don't have them a minshao would work well. the n start throwing dusk balls
i used a dusk ball but you could use a timer ball a couple of times or an ultra ball when you get it's health down
you should use it on lugia. he is the hardest one to catch. you cant catch him with any other pokeball. you can only catch him with a master ball.
Master Ball
The best ball to catch Deoxys is a Master Ball or a Timer Ball! Trust Me!!! Pokemon Master
You should use a Master Ball or a ton of Ultra Balls and you might get lucky.
An ultra ball
masterball
Dusk balls
masterball or time ball