Demon Dread Weapon

The Gates of Hell (Dice Freaks)
Grimoire of Cosmic Entities Volume One By Eli Atkinson, William Church and Serge W. Desir, Jr.
Original Concept by Serge W. Desir, Jr.
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As with a demon bane weapon, a demon dread weapon excels at attacking demons. Against such foes, its effective enhancement bonus increases by +6, and it deals an additional +6d6 points of damage. If it scores a successful critical hit against the foe, that creature must make a Fortitude save (DC 27) or be destroyed instantly and turned to dust. (This even affects creatures immune to critical hits or death magic.) Bows, cross-bows and slings so crafted bestow the bane quality upon their ammunition.

Overwhelming Conjuration; CL 24th; Craft Magic Arms and Armour, summon monster IX; Price +7 bonus.