Yes, Dusk Balls actually work better when it's dark, at night and in caves etc.
you cant you need to use some kind of pokeball
you cant, you will need a master ball. I wasted mine catching Dialga yes u can use a heal ball i did it b4 im proved by pkmn master
you can, but you need a dive ball
if you are talking about giratina, you cant. the only way to get him is to transfer from Pokemon platinum pearl and diamond
You cant catch any trainers Pokemon
You cant catch diaglia or palkia. The only way is the arceus event. When it comes out you get to choose diaglia, palkia or Giratina. That sucks^
you cant
you cant. the trainer will block the ball.
its a trainers Pokemon so you cant catch it you can only catch wild Pokemon - awnser by softy312
fill your pokedex if you cant get the last three (darkrai,arcues,and shaymin then email me at sentakahishi@yahoo.com and ill tell ya how)
you cant
you cant because they gave you the orbs so if you got the pokemon on diamond or pearl you would transfer it to this game and then you give them the orb