Assuming your Buff looks something like this:
INI:
Buffs1=Voice of Perspicacity
You can add a condition to it like this:
INI:
Buffs1=Voice of Perspicacity|cond1
And then go to your KA Conditions section and add the following conditional:
INI:
Cond1=!${Me.Buff[Voice of Sagacity].ID} || !${Me.Buff[Sagacity].ID}
Notice that in this conditional I included a check for the group OR single cast version against what your enchanter has on (via "me"). The only thing to keep in mind here is that it checks what buff you personally have on, unless you feel like adding other checks for the ma/tank or whatever (which I honestly don't recommend since it's will just bloat things up). But at least this should give you a fairly good idea or be useful as is to you.