help on bcnm 30 in ghelsba outpost

[jenovabldrb]

ok people i need the dispel scroll soon and i saw that this bcnm drops it but i have never fought a bcnm before (excepth those dragons for rank 2 mission 3).

1. how do i get the orbs for it
2. what should be in my party (rdm(me) and 2 other people)
3. should i sub theif for better drops or sub blm or whm

thanks for your help