Per game yea, but you can always trade it.
Theres 2 Masterballs One Team Aqua Hideout The Other Is At Department store loto corner you need to get all 6 numbers right
Technically there's infinite master balls because you can win one from the lottery in lilycove city in the dept store.
Yes you can but to get two you need to trade for a Pokemon that holding a master ball. Hope I helped.
Clone them using action replay
if you go to the T.V. station @ jubilife city if you get this ID number thing you might be able to get a master ball. there is one problem though. it is very very very very VERY rare.