Use an Ultra Ball, not a Master Ball
I caught it with an ultra ball. Best is to lower it's HP and catch it or put him to sleep. but you need 10-15 ultra balls or more. Depends on his HP.
You would need to get the Action Relplay at GameStop.
other than a masterball probaly with a hacked ball cherish or ultra,timer,heal,and quick ball
Using a Great Ball is the best way. Actually a Ultra ball is the best way.
Yes it can, it would be easier to catch Registeel with a Ultra Ball than with a normal PokéBall.
The best pokeball to catch registeel is a repeat ball if you have owned a registeel before trust me it will work wonders for you i caught registeel with a repeat ball without even weakning it.
master ball
Weaken it then use many great balls or pokeballs or timerballs if you own a registeel from a friend try using a repeat ball. This is no joke when i tried to catch registeel i already owned one from a friend and i just threw a repeat ball and i caught it on the first try.
Ultra ball.
Yes. It is completely possible to catch Mewtwo with an ultra ball.
a quick ball or a master ball
No. They have the same catch rate as all the other legendary Pokemon. However, they are all in caves, so you can use a dusk ball which has twice the catch rate as an ultra ball (only in caves or at night) and is 200 poke-currency cheaper than an ultra ball. You could still get lucky with an ultra ball, but if I was using ultra balls, I would bring at least 40 of them, a Pokemon with hypnosis (or some equivalent), maybe false swipe, and save before you try! You could probably be fine with just 30 dusk balls.
ultra ball
get a ultra ball lower its hp to half and throw the ultra ball
1st:Throw the Ultra Ball 2nd:See if it catches it Easy.
NO! I recommend a dusk ball!