You buy them when you beat your 4th gym
You catch them with a ultra ball
with skill yeah
You cannot get a Love Ball in Pokémon Black and White.
the master ball is for zekrom in white and reshiram in black
take down its health then put it to sleep or confuse it
No
ultra, the premier is the same as a pokeball
The best pokeball to catch victini in white/black is the ultra ball or the great ball you shouldn't use the master ball.
In white you use the master ball in black you trade
professor juniper gives it to you
on Pokemon black, how to get reshiram is to beat the elite four, and in team plasma's castle, where n is, reshiram will bust through everything and confront you. SAVE FIRST!!!!! when you catch it(i suggest with an ultra ball, i got it with only 2 ultras) n will heal your Pokemon and will battle you. same thing for white, but not reshiram, it's zekrom.
In Black, White, Black 2 and White 2, you cannot keep a Pokémon outside of its Poké Ball.