I thought it was fine as it was originally. Basically its a weapon with the bless weapon paladin spell on it permanently. What surprises me is that you don't have that spell as the pre-requisite. Sure its not a cleric spell. But it causes the cleric to have to work in conjunction with a paladin to create such a weapon. That somehow seems appropriate.
Because there is not "curse weapon" equivalent for blackguards, bane is a good substitute.
I don't find it overpowered based on the weapon. That's the same thing as saying and of the burst enhancements are overpowered for the same reason. Some weapons are just better.
Bless weapon is only a 1st-level spell. The +1 modifier is just fine, provided you have the alignment restriction that "blessed" can only be wielded by good and "defiled" can only be wielded by evil.
Because there is not "curse weapon" equivalent for blackguards, bane is a good substitute.
I don't find it overpowered based on the weapon. That's the same thing as saying and of the burst enhancements are overpowered for the same reason. Some weapons are just better.
Bless weapon is only a 1st-level spell. The +1 modifier is just fine, provided you have the alignment restriction that "blessed" can only be wielded by good and "defiled" can only be wielded by evil.