if can get bn-op only with pvp comp ok but i think some players got many bn-op in shop before
and it easily maked some players get so much more critical skill without any using credits and without upgrade skill
You're right, we had packets containing the BN operation, but, as you may have seen in the past, such packets are not the norm.
The BN-OP is, as the most powerful weapon, still thought to be rare, difficult and slow to obtain (By placing first in the PvP Competition).