Well, she keeps her health just like Mesprit, so put a haunter/gengar at the front of your party (because those pokémon have real high speed) at a higher level than Creselia, so that it has a higher speed than Creselia. Therefore, your pokémon goes first. Give your haunter/gengar these following moves: Mean Look, Hypnosis, Dream Eater, and Night Shade. You use Mean Look first to make her not run away, then Hypnosis just as a precaution, then Dream Eater and Night Shade until she's down to red! (Ghost moves are super effective against her so watch her health closely) Once she's in red, throw a Poké Ball or whatever you have at her (you may have to throw several, so just use Mean Look every now and then) and then you've got her!
also you can use trapinch but dont switch it out and dont evolve it or you can use sudowoodo and use block.
no
Of course, a Master Ball catches any Pokemon without fail, Legendary or not.
Yes, you can catch Dialga without a Master Ball. Dialga can be caught with any kind of Poké Ball but Dusk Balls and Ultra Balls would be the better options.
Any Pokémon is catchable without the Master Ball, though some-especially Legendaries-are harder than others.
no it won't be holding a master ball cos when you used the master ball to catch a certain Pokemon, the master ball will be gone in your inventory because it is a consumable.
no
I'm not quite sure what your talking about, but I would have to say that you would not have to catch it in a Master Ball.
Yes
you need to have two master balls.
Use an Ultra Ball, not a Master Ball
yes, i caught suicine with a friend ball!
Of course, a Master Ball catches any Pokemon without fail, Legendary or not.
This is impossible without the use of cheat codes, unfortunately. Only the Master Ball can catch Pokemon without fail.
not without a gameshark
You use a master ball
Yes, you can catch Dialga without a Master Ball. Dialga can be caught with any kind of Poké Ball but Dusk Balls and Ultra Balls would be the better options.
Any Pokémon is catchable without the Master Ball, though some-especially Legendaries-are harder than others.