These are a matched pair of +2 longswords, one cold iron, one silver, which improve to +5 Unholy longswords in the hands of a Blackguard or other champion of an evil god. The handles are wrapped in supple black leather straps braided around ebony. In place of a more typical hand guard, each sword has three arrow-like spines which extend from the handle away from the hand. Their pommels are wide iron spikes which may be used to make an unarmed attack which deals lethal damage and ignores hardness.
When used together by a blackguard (or other champion of an evil god or cause) these swords provide spell resistance of 5 + the blackguard’s level to the wielder and anyone adjacent to her. It also enables the wielder to use greater dispel magic (once per round as a standard action) at the character level of the blackguard. (Only the area dispel is possible, not the targeted dispel or counterspell versions of greater dispel magic.)
CL 18, unholy aura, +2 weapons, 120,945 gp