50 plus trades.
you can get one when you defeat iris or do 50 trades an talk to some black suited guy in castelias pokemon center
There are two. One can be gained by speaking to Professor Juniper after you have gained all 8 Unova badges. The other is given by the gift-giving man in Castelia, he gives you rewards after a certain number of pokemon trades, the Masterball is the last one after 50 trades.
Make 50+ trades in the global trade station, then talk to the agent in the pkmn Centre of Castelia city (2nd floor). He will also give many other items
at level 50
50
Shelgon evolves into Salamence at level 50 in Pokemon black 2.
Victory Road.
level 50
lvl 50
you level it up 50
Level 50
global trades! THE WILL TELL YOU HOW TO START AND FINISH I BEAT THE GAME SO IM ON 51-100 50 HALF WAY THROUGH 1-49 BEGINNERS A1-49 B50 C51-100