trade with 50 people. Next, you go to castielia city which is next to skyarrow bridge and route 4. talk to the man next to the union room. he will give you a master ball.
the master ball is for zekrom in white and reshiram in black
yes, you can catch ANY pokemon with a master ball, reshiram is who it is aimed at in white 2
Professor Juniper gives you a master ball after defeating Iris/Drayden. An agent in the Pokemon Centre of Castelia City will give another after you make 50+ trades in the GTS
You cannot find a second master ball however you can trade Pokemon to get another Pokemon with a master ball or use an action replay
you can trade a Pokemon from black or white holding a master ball.
with master baLL
there's only one but you can trad a Pokemon holding a master ball from another game
you could save before getting it, get the master ball, have a Pokemon hold it, trade that Pokemon, turn game off then back on, get another master ball, and trade Pokemon back.
Usually by trading a Pokemon carrying a Master Ball from a different Pokemon game.
Yes you can I have done it
You can't!!
don't have the game