So, Pactseeker's Blade is a +2 cruel longsword from Blood of the Coven that also counts as cold iron. When it deals damage, it also deals damage to any other enemies that share a bond to the struck target - a shared buff spell, in the same coven, etc.
I have another question in the Rules forum for whether that shared damage would trigger cruel.
Question: even if all affected enemies become sickened from cruel...that's an expensive effect. A Cold Iron +2 Cruel longsword would be ~21,000, which would make the "damage other creatures by 5-7 pts max if they share a bond" a +2 property, or ~34,000... Does that seem inline?
If cruel does not transfer, I really do not see the point of this weapon...