Only 1! Some recommend using it to catch Ho-oh, Lugia, Mewtwo, Groudon, etc. But I was able to catch Ho-oh just by paralyzing it, bringing it's health down to the red and throwing 3 Ultra Balls at it. Then I caught Mewtwo with the same tactic except I didn't even have to use Ultra Balls, I used 1 friend ball (super weak poke balls)! Plus he can be traded from old versions pretty easily. I also caught Moltres with Ultra Balls and don't plan on wasting the MB on any of the HG/SS legendarys. I think I will trade to an older version so I can capture multiple Legendarys from those versions in one playthrough and then trade them to HG/SS.
You can get an infinite amount of master balls in Pokemon HeartGold, though you can only be sure that you get at least one.
The Lotto Corner at the Goldenrod Radio Tower will give you a master ball all the ID numbers of one Pokemon match the daily ID number. This is extremely tough to get, but it is possible to get an infinite amount if you keep matching all the numbers every day.
You get one from the prof. twards the last gym. Also you can use the action replay for the pokeball cheat. Which means you can get a total of 1,000 pokeballs in the game.
Actually, you can get 1,001. There is a man-correct me if I'm wrong, I think he's in one of the Poke Centers-and if you have traded w/ at least 50 different people, he gives you a Master Ball.
You can get 2 Master Balls in both versions.
XD
Do you mean articuno then simply use many ultra balls after weakening it.
The normal 1 from Professor Juniper in Mistralton.
Since Mewtwo is in a cave, try using Dusk balls. If it doesn't work, Master ball. If you already used the Master ball, then buy as many Dusk balls as you can and try to catch it. If your patient enough, try catching Mewtwo with full health.
i masterball
You can get 2 Master Balls in both versions.
you can get 1 master ball
First you get the one master ball then you either trade Pokemon with a friend who's Pokemon are holding the master ball, take it off, trade back and repeat this many times or you can use a gameshark or clone it.
1
1
one
You can clone a Pokemon with the master ball or trade it to a friend and keep starting over until you're satisfied with the number of master balls.
Attach your master ball to ONE POKEMON, next CLONE that Pokemon for how many master balls you want. Next detach them, and release all the clones (if you want)
Duplicate Pokemon with a masterball attached to them.
I think you can get only one.
Only one.