Shattermantle

A shattermantle weapon was one with the power to damage the mantle of spell resistance around an enemy with each strike.

Description
Weapons with this power sparked with writhing blue energy within the material of the weapon itself.

The cheapest of shadowmantle weapons sold for at least 2,300 gold pieces.

Powers
These weapons had the power to reduce the spell resistance of any creature struck by a small amount. This reduction was only temporary, lasting about six seconds, but multiple repeated strikes in a short time frame did cumulative damage to the resistance. The attacker had no way of knowing how much the blow had reduced the opponent's resistance.

Creation
Magic-weapon crafters who desired to forge such weapons had to already be skilled at overcoming the spell resistances of others. On other worlds, an identical weapon property could be achieved by crafting a weapon with the spell assay spell resistance, but this was not the technique used in Waterdeep, from where these Art-crafted weapons were developed.

Notable Shattermantle Weapons
The Quarterstaff of Alcedor had one of its two ends enchanted with this power.

The aasimar paladin Xale of the Starry Glen, a member of the Knights of the Blue Moon, bore a shattermantle lance in battle from upon his celestial griffon Arimaspea.